diff --git a/objectivec/GPBCodedOutputStream.h b/objectivec/GPBCodedOutputStream.h
index a5aef17..0a47f1c 100644
--- a/objectivec/GPBCodedOutputStream.h
+++ b/objectivec/GPBCodedOutputStream.h
@@ -168,26 +168,26 @@
 - (void)writeEnumNoTag:(int32_t)value;
 
 - (void)writeString:(int32_t)fieldNumber value:(NSString *)value;
-- (void)writeStringArray:(int32_t)fieldNumber values:(NSArray *)values;
+- (void)writeStringArray:(int32_t)fieldNumber values:(NSArray<NSString*> *)values;
 - (void)writeStringNoTag:(NSString *)value;
 
 - (void)writeMessage:(int32_t)fieldNumber value:(GPBMessage *)value;
-- (void)writeMessageArray:(int32_t)fieldNumber values:(NSArray *)values;
+- (void)writeMessageArray:(int32_t)fieldNumber values:(NSArray<GPBMessage*> *)values;
 - (void)writeMessageNoTag:(GPBMessage *)value;
 
 - (void)writeBytes:(int32_t)fieldNumber value:(NSData *)value;
-- (void)writeBytesArray:(int32_t)fieldNumber values:(NSArray *)values;
+- (void)writeBytesArray:(int32_t)fieldNumber values:(NSArray<NSData*> *)values;
 - (void)writeBytesNoTag:(NSData *)value;
 
 - (void)writeGroup:(int32_t)fieldNumber
              value:(GPBMessage *)value;
-- (void)writeGroupArray:(int32_t)fieldNumber values:(NSArray *)values;
+- (void)writeGroupArray:(int32_t)fieldNumber values:(NSArray<GPBMessage*> *)values;
 - (void)writeGroupNoTag:(int32_t)fieldNumber
                   value:(GPBMessage *)value;
 
 - (void)writeUnknownGroup:(int32_t)fieldNumber
                     value:(GPBUnknownFieldSet *)value;
-- (void)writeUnknownGroupArray:(int32_t)fieldNumber values:(NSArray *)values;
+- (void)writeUnknownGroupArray:(int32_t)fieldNumber values:(NSArray<GPBUnknownFieldSet*> *)values;
 - (void)writeUnknownGroupNoTag:(int32_t)fieldNumber
                          value:(GPBUnknownFieldSet *)value;
 
@@ -306,17 +306,17 @@
 //%
 // Write methods for types that aren't in packed arrays.
 //%PDDM-DEFINE _WRITE_UNPACKABLE_DECLS(NAME, TYPE)
-//%- (void)write##NAME:(int32_t)fieldNumber value:(TYPE)value;
-//%- (void)write##NAME##Array:(int32_t)fieldNumber values:(NSArray *)values;
-//%- (void)write##NAME##NoTag:(TYPE)value;
+//%- (void)write##NAME:(int32_t)fieldNumber value:(TYPE *)value;
+//%- (void)write##NAME##Array:(int32_t)fieldNumber values:(NSArray<##TYPE##*> *)values;
+//%- (void)write##NAME##NoTag:(TYPE *)value;
 //%
 // Special write methods for Groups.
 //%PDDM-DEFINE _WRITE_GROUP_DECLS(NAME, TYPE)
 //%- (void)write##NAME:(int32_t)fieldNumber
-//%       NAME$S value:(TYPE)value;
-//%- (void)write##NAME##Array:(int32_t)fieldNumber values:(NSArray *)values;
+//%       NAME$S value:(TYPE *)value;
+//%- (void)write##NAME##Array:(int32_t)fieldNumber values:(NSArray<##TYPE##*> *)values;
 //%- (void)write##NAME##NoTag:(int32_t)fieldNumber
-//%            NAME$S value:(TYPE)value;
+//%            NAME$S value:(TYPE *)value;
 //%
 
 // One macro to hide it all up above.
@@ -335,8 +335,8 @@
 //%_WRITE_PACKABLE_DECLS(SFixed32, Int32, int32_t)
 //%_WRITE_PACKABLE_DECLS(Bool, Bool, BOOL)
 //%_WRITE_PACKABLE_DECLS(Enum, Enum, int32_t)
-//%_WRITE_UNPACKABLE_DECLS(String, NSString *)
-//%_WRITE_UNPACKABLE_DECLS(Message, GPBMessage *)
-//%_WRITE_UNPACKABLE_DECLS(Bytes, NSData *)
-//%_WRITE_GROUP_DECLS(Group, GPBMessage *)
-//%_WRITE_GROUP_DECLS(UnknownGroup, GPBUnknownFieldSet *)
+//%_WRITE_UNPACKABLE_DECLS(String, NSString)
+//%_WRITE_UNPACKABLE_DECLS(Message, GPBMessage)
+//%_WRITE_UNPACKABLE_DECLS(Bytes, NSData)
+//%_WRITE_GROUP_DECLS(Group, GPBMessage)
+//%_WRITE_GROUP_DECLS(UnknownGroup, GPBUnknownFieldSet)
diff --git a/objectivec/GPBDescriptor.h b/objectivec/GPBDescriptor.h
index 360afe9..8d8e975 100644
--- a/objectivec/GPBDescriptor.h
+++ b/objectivec/GPBDescriptor.h
@@ -55,9 +55,9 @@
 @interface GPBDescriptor : NSObject<NSCopying>
 
 @property(nonatomic, readonly, copy) NSString *name;
-@property(nonatomic, readonly, strong, nullable) NSArray *fields;
-@property(nonatomic, readonly, strong, nullable) NSArray *oneofs;
-@property(nonatomic, readonly, strong, nullable) NSArray *enums;
+@property(nonatomic, readonly, strong, nullable) NSArray<GPBFieldDescriptor*> *fields;
+@property(nonatomic, readonly, strong, nullable) NSArray<GPBOneofDescriptor*> *oneofs;
+@property(nonatomic, readonly, strong, nullable) NSArray<GPBEnumDescriptor*> *enums;
 @property(nonatomic, readonly, nullable) const GPBExtensionRange *extensionRanges;
 @property(nonatomic, readonly) NSUInteger extensionRangesCount;
 @property(nonatomic, readonly, assign) GPBFileDescriptor *file;
@@ -81,7 +81,7 @@
 
 @interface GPBOneofDescriptor : NSObject
 @property(nonatomic, readonly) NSString *name;
-@property(nonatomic, readonly) NSArray *fields;
+@property(nonatomic, readonly) NSArray<GPBFieldDescriptor*> *fields;
 
 - (nullable GPBFieldDescriptor *)fieldWithNumber:(uint32_t)fieldNumber;
 - (nullable GPBFieldDescriptor *)fieldWithName:(NSString *)name;
diff --git a/objectivec/GPBDictionary.h b/objectivec/GPBDictionary.h
index 6961cfc..3120814 100644
--- a/objectivec/GPBDictionary.h
+++ b/objectivec/GPBDictionary.h
@@ -355,33 +355,33 @@
 
 #pragma mark - UInt32 -> Object
 
-@interface GPBUInt32ObjectDictionary : NSObject <NSCopying>
+@interface GPBUInt32ObjectDictionary<__covariant ObjectType> : NSObject <NSCopying>
 
 @property(nonatomic, readonly) NSUInteger count;
 
 + (instancetype)dictionary;
-+ (instancetype)dictionaryWithObject:(id)object
++ (instancetype)dictionaryWithObject:(ObjectType)object
                               forKey:(uint32_t)key;
-+ (instancetype)dictionaryWithObjects:(const id GPB_UNSAFE_UNRETAINED [])objects
++ (instancetype)dictionaryWithObjects:(const ObjectType GPB_UNSAFE_UNRETAINED [])objects
                               forKeys:(const uint32_t [])keys
                                 count:(NSUInteger)count;
 + (instancetype)dictionaryWithDictionary:(GPBUInt32ObjectDictionary *)dictionary;
 + (instancetype)dictionaryWithCapacity:(NSUInteger)numItems;
 
-- (instancetype)initWithObjects:(const id GPB_UNSAFE_UNRETAINED [])objects
+- (instancetype)initWithObjects:(const ObjectType GPB_UNSAFE_UNRETAINED [])objects
                         forKeys:(const uint32_t [])keys
                           count:(NSUInteger)count NS_DESIGNATED_INITIALIZER;
 - (instancetype)initWithDictionary:(GPBUInt32ObjectDictionary *)dictionary;
 - (instancetype)initWithCapacity:(NSUInteger)numItems;
 
-- (id)objectForKey:(uint32_t)key;
+- (ObjectType)objectForKey:(uint32_t)key;
 
 - (void)enumerateKeysAndObjectsUsingBlock:
-    (void (^)(uint32_t key, id object, BOOL *stop))block;
+    (void (^)(uint32_t key, ObjectType object, BOOL *stop))block;
 
 - (void)addEntriesFromDictionary:(GPBUInt32ObjectDictionary *)otherDictionary;
 
-- (void)setObject:(id)object forKey:(uint32_t)key;
+- (void)setObject:(ObjectType)object forKey:(uint32_t)key;
 
 - (void)removeObjectForKey:(uint32_t)aKey;
 - (void)removeAll;
@@ -701,33 +701,33 @@
 
 #pragma mark - Int32 -> Object
 
-@interface GPBInt32ObjectDictionary : NSObject <NSCopying>
+@interface GPBInt32ObjectDictionary<__covariant ObjectType> : NSObject <NSCopying>
 
 @property(nonatomic, readonly) NSUInteger count;
 
 + (instancetype)dictionary;
-+ (instancetype)dictionaryWithObject:(id)object
++ (instancetype)dictionaryWithObject:(ObjectType)object
                               forKey:(int32_t)key;
-+ (instancetype)dictionaryWithObjects:(const id GPB_UNSAFE_UNRETAINED [])objects
++ (instancetype)dictionaryWithObjects:(const ObjectType GPB_UNSAFE_UNRETAINED [])objects
                               forKeys:(const int32_t [])keys
                                 count:(NSUInteger)count;
 + (instancetype)dictionaryWithDictionary:(GPBInt32ObjectDictionary *)dictionary;
 + (instancetype)dictionaryWithCapacity:(NSUInteger)numItems;
 
-- (instancetype)initWithObjects:(const id GPB_UNSAFE_UNRETAINED [])objects
+- (instancetype)initWithObjects:(const ObjectType GPB_UNSAFE_UNRETAINED [])objects
                         forKeys:(const int32_t [])keys
                           count:(NSUInteger)count NS_DESIGNATED_INITIALIZER;
 - (instancetype)initWithDictionary:(GPBInt32ObjectDictionary *)dictionary;
 - (instancetype)initWithCapacity:(NSUInteger)numItems;
 
-- (id)objectForKey:(int32_t)key;
+- (ObjectType)objectForKey:(int32_t)key;
 
 - (void)enumerateKeysAndObjectsUsingBlock:
-    (void (^)(int32_t key, id object, BOOL *stop))block;
+    (void (^)(int32_t key, ObjectType object, BOOL *stop))block;
 
 - (void)addEntriesFromDictionary:(GPBInt32ObjectDictionary *)otherDictionary;
 
-- (void)setObject:(id)object forKey:(int32_t)key;
+- (void)setObject:(ObjectType)object forKey:(int32_t)key;
 
 - (void)removeObjectForKey:(int32_t)aKey;
 - (void)removeAll;
@@ -1047,33 +1047,33 @@
 
 #pragma mark - UInt64 -> Object
 
-@interface GPBUInt64ObjectDictionary : NSObject <NSCopying>
+@interface GPBUInt64ObjectDictionary<__covariant ObjectType> : NSObject <NSCopying>
 
 @property(nonatomic, readonly) NSUInteger count;
 
 + (instancetype)dictionary;
-+ (instancetype)dictionaryWithObject:(id)object
++ (instancetype)dictionaryWithObject:(ObjectType)object
                               forKey:(uint64_t)key;
-+ (instancetype)dictionaryWithObjects:(const id GPB_UNSAFE_UNRETAINED [])objects
++ (instancetype)dictionaryWithObjects:(const ObjectType GPB_UNSAFE_UNRETAINED [])objects
                               forKeys:(const uint64_t [])keys
                                 count:(NSUInteger)count;
 + (instancetype)dictionaryWithDictionary:(GPBUInt64ObjectDictionary *)dictionary;
 + (instancetype)dictionaryWithCapacity:(NSUInteger)numItems;
 
-- (instancetype)initWithObjects:(const id GPB_UNSAFE_UNRETAINED [])objects
+- (instancetype)initWithObjects:(const ObjectType GPB_UNSAFE_UNRETAINED [])objects
                         forKeys:(const uint64_t [])keys
                           count:(NSUInteger)count NS_DESIGNATED_INITIALIZER;
 - (instancetype)initWithDictionary:(GPBUInt64ObjectDictionary *)dictionary;
 - (instancetype)initWithCapacity:(NSUInteger)numItems;
 
-- (id)objectForKey:(uint64_t)key;
+- (ObjectType)objectForKey:(uint64_t)key;
 
 - (void)enumerateKeysAndObjectsUsingBlock:
-    (void (^)(uint64_t key, id object, BOOL *stop))block;
+    (void (^)(uint64_t key, ObjectType object, BOOL *stop))block;
 
 - (void)addEntriesFromDictionary:(GPBUInt64ObjectDictionary *)otherDictionary;
 
-- (void)setObject:(id)object forKey:(uint64_t)key;
+- (void)setObject:(ObjectType)object forKey:(uint64_t)key;
 
 - (void)removeObjectForKey:(uint64_t)aKey;
 - (void)removeAll;
@@ -1393,33 +1393,33 @@
 
 #pragma mark - Int64 -> Object
 
-@interface GPBInt64ObjectDictionary : NSObject <NSCopying>
+@interface GPBInt64ObjectDictionary<__covariant ObjectType> : NSObject <NSCopying>
 
 @property(nonatomic, readonly) NSUInteger count;
 
 + (instancetype)dictionary;
-+ (instancetype)dictionaryWithObject:(id)object
++ (instancetype)dictionaryWithObject:(ObjectType)object
                               forKey:(int64_t)key;
-+ (instancetype)dictionaryWithObjects:(const id GPB_UNSAFE_UNRETAINED [])objects
++ (instancetype)dictionaryWithObjects:(const ObjectType GPB_UNSAFE_UNRETAINED [])objects
                               forKeys:(const int64_t [])keys
                                 count:(NSUInteger)count;
 + (instancetype)dictionaryWithDictionary:(GPBInt64ObjectDictionary *)dictionary;
 + (instancetype)dictionaryWithCapacity:(NSUInteger)numItems;
 
-- (instancetype)initWithObjects:(const id GPB_UNSAFE_UNRETAINED [])objects
+- (instancetype)initWithObjects:(const ObjectType GPB_UNSAFE_UNRETAINED [])objects
                         forKeys:(const int64_t [])keys
                           count:(NSUInteger)count NS_DESIGNATED_INITIALIZER;
 - (instancetype)initWithDictionary:(GPBInt64ObjectDictionary *)dictionary;
 - (instancetype)initWithCapacity:(NSUInteger)numItems;
 
-- (id)objectForKey:(int64_t)key;
+- (ObjectType)objectForKey:(int64_t)key;
 
 - (void)enumerateKeysAndObjectsUsingBlock:
-    (void (^)(int64_t key, id object, BOOL *stop))block;
+    (void (^)(int64_t key, ObjectType object, BOOL *stop))block;
 
 - (void)addEntriesFromDictionary:(GPBInt64ObjectDictionary *)otherDictionary;
 
-- (void)setObject:(id)object forKey:(int64_t)key;
+- (void)setObject:(ObjectType)object forKey:(int64_t)key;
 
 - (void)removeObjectForKey:(int64_t)aKey;
 - (void)removeAll;
@@ -1739,33 +1739,33 @@
 
 #pragma mark - Bool -> Object
 
-@interface GPBBoolObjectDictionary : NSObject <NSCopying>
+@interface GPBBoolObjectDictionary<__covariant ObjectType> : NSObject <NSCopying>
 
 @property(nonatomic, readonly) NSUInteger count;
 
 + (instancetype)dictionary;
-+ (instancetype)dictionaryWithObject:(id)object
++ (instancetype)dictionaryWithObject:(ObjectType)object
                               forKey:(BOOL)key;
-+ (instancetype)dictionaryWithObjects:(const id GPB_UNSAFE_UNRETAINED [])objects
++ (instancetype)dictionaryWithObjects:(const ObjectType GPB_UNSAFE_UNRETAINED [])objects
                               forKeys:(const BOOL [])keys
                                 count:(NSUInteger)count;
 + (instancetype)dictionaryWithDictionary:(GPBBoolObjectDictionary *)dictionary;
 + (instancetype)dictionaryWithCapacity:(NSUInteger)numItems;
 
-- (instancetype)initWithObjects:(const id GPB_UNSAFE_UNRETAINED [])objects
+- (instancetype)initWithObjects:(const ObjectType GPB_UNSAFE_UNRETAINED [])objects
                         forKeys:(const BOOL [])keys
                           count:(NSUInteger)count NS_DESIGNATED_INITIALIZER;
 - (instancetype)initWithDictionary:(GPBBoolObjectDictionary *)dictionary;
 - (instancetype)initWithCapacity:(NSUInteger)numItems;
 
-- (id)objectForKey:(BOOL)key;
+- (ObjectType)objectForKey:(BOOL)key;
 
 - (void)enumerateKeysAndObjectsUsingBlock:
-    (void (^)(BOOL key, id object, BOOL *stop))block;
+    (void (^)(BOOL key, ObjectType object, BOOL *stop))block;
 
 - (void)addEntriesFromDictionary:(GPBBoolObjectDictionary *)otherDictionary;
 
-- (void)setObject:(id)object forKey:(BOOL)key;
+- (void)setObject:(ObjectType)object forKey:(BOOL)key;
 
 - (void)removeObjectForKey:(BOOL)aKey;
 - (void)removeAll;
@@ -2096,7 +2096,7 @@
 //%DICTIONARY_POD_INTERFACES_FOR_KEY(String, NSString, *, OBJECT)
 //%PDDM-DEFINE DICTIONARY_INTERFACES_FOR_POD_KEY(KEY_NAME, KEY_TYPE)
 //%DICTIONARY_POD_INTERFACES_FOR_KEY(KEY_NAME, KEY_TYPE, , POD)
-//%DICTIONARY_POD_KEY_TO_OBJECT_INTERFACE(KEY_NAME, KEY_TYPE, Object, id)
+//%DICTIONARY_POD_KEY_TO_OBJECT_INTERFACE(KEY_NAME, KEY_TYPE, Object, ObjectType)
 //%PDDM-DEFINE DICTIONARY_POD_INTERFACES_FOR_KEY(KEY_NAME, KEY_TYPE, KisP, KHELPER)
 //%DICTIONARY_KEY_TO_POD_INTERFACE(KEY_NAME, KEY_TYPE, KisP, KHELPER, UInt32, uint32_t)
 //%DICTIONARY_KEY_TO_POD_INTERFACE(KEY_NAME, KEY_TYPE, KisP, KHELPER, Int32, int32_t)
@@ -2122,10 +2122,16 @@
 // Nothing
 //%PDDM-DEFINE ARRAY_ARG_MODIFIEROBJECT()
 //%GPB_UNSAFE_UNRETAINED ##
+//%PDDM-DEFINE DICTIONARY_CLASS_DECLPOD(KEY_NAME, VALUE_NAME, VALUE_TYPE)
+//%GPB##KEY_NAME##VALUE_NAME##Dictionary
+//%PDDM-DEFINE DICTIONARY_CLASS_DECLEnum(KEY_NAME, VALUE_NAME, VALUE_TYPE)
+//%GPB##KEY_NAME##VALUE_NAME##Dictionary
+//%PDDM-DEFINE DICTIONARY_CLASS_DECLOBJECT(KEY_NAME, VALUE_NAME, VALUE_TYPE)
+//%GPB##KEY_NAME##VALUE_NAME##Dictionary<__covariant VALUE_TYPE>
 //%PDDM-DEFINE DICTIONARY_COMMON_INTERFACE(KEY_NAME, KEY_TYPE, KisP, KHELPER, VALUE_NAME, VALUE_TYPE, VHELPER, VNAME)
 //%#pragma mark - KEY_NAME -> VALUE_NAME
 //%
-//%@interface GPB##KEY_NAME##VALUE_NAME##Dictionary : NSObject <NSCopying>
+//%@interface DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) : NSObject <NSCopying>
 //%
 //%@property(nonatomic, readonly) NSUInteger count;
 //%
diff --git a/objectivec/GPBUnknownField.h b/objectivec/GPBUnknownField.h
index 12d72a9..43709ee 100644
--- a/objectivec/GPBUnknownField.h
+++ b/objectivec/GPBUnknownField.h
@@ -45,8 +45,8 @@
 @property(nonatomic, readonly, strong) GPBUInt64Array *varintList;
 @property(nonatomic, readonly, strong) GPBUInt32Array *fixed32List;
 @property(nonatomic, readonly, strong) GPBUInt64Array *fixed64List;
-@property(nonatomic, readonly, strong) NSArray *lengthDelimitedList;  // NSData
-@property(nonatomic, readonly, strong) NSArray *groupList;  // GPBUnknownFieldSet
+@property(nonatomic, readonly, strong) NSArray<NSData*> *lengthDelimitedList;
+@property(nonatomic, readonly, strong) NSArray<GPBUnknownFieldSet*> *groupList;
 
 // Only one of these should be used per Field.
 - (void)addVarint:(uint64_t)value;
diff --git a/objectivec/GPBUnknownField.m b/objectivec/GPBUnknownField.m
index c49c0df..22ed66a 100644
--- a/objectivec/GPBUnknownField.m
+++ b/objectivec/GPBUnknownField.m
@@ -39,8 +39,8 @@
   GPBUInt64Array *mutableVarintList_;
   GPBUInt32Array *mutableFixed32List_;
   GPBUInt64Array *mutableFixed64List_;
-  NSMutableArray *mutableLengthDelimitedList_;
-  NSMutableArray *mutableGroupList_;
+  NSMutableArray<NSData*> *mutableLengthDelimitedList_;
+  NSMutableArray<GPBUnknownFieldSet*> *mutableGroupList_;
 }
 
 @synthesize number = number_;
diff --git a/objectivec/GPBUnknownFieldSet.h b/objectivec/GPBUnknownFieldSet.h
index d785ca1..8db0132 100644
--- a/objectivec/GPBUnknownFieldSet.h
+++ b/objectivec/GPBUnknownFieldSet.h
@@ -42,8 +42,8 @@
 
 - (void)addField:(GPBUnknownField *)field;
 
-// Returns an NSArray of the GPBFields sorted by the field numbers.
-- (NSArray *)sortedFields;
+// Returns an NSArray of the GPBUnknownFields sorted by the field numbers.
+- (NSArray<GPBUnknownField*> *)sortedFields;
 
 @end
 
diff --git a/objectivec/Tests/GPBDictionaryTests+Bool.m b/objectivec/Tests/GPBDictionaryTests+Bool.m
index 8b1900f..afa3d11 100644
--- a/objectivec/Tests/GPBDictionaryTests+Bool.m
+++ b/objectivec/Tests/GPBDictionaryTests+Bool.m
@@ -2147,7 +2147,7 @@
 
 @end
 
-//%PDDM-EXPAND TESTS_FOR_BOOL_KEY_OBJECT_VALUE(Object, id, @"abc", @"def")
+//%PDDM-EXPAND TESTS_FOR_BOOL_KEY_OBJECT_VALUE(Object, NSString*, @"abc", @"def")
 // This block of code is generated, do not edit it directly.
 
 #pragma mark - Bool -> Object
@@ -2158,11 +2158,11 @@
 @implementation GPBBoolObjectDictionaryTests
 
 - (void)testEmpty {
-  GPBBoolObjectDictionary *dict = [[GPBBoolObjectDictionary alloc] init];
+  GPBBoolObjectDictionary<NSString*> *dict = [[GPBBoolObjectDictionary alloc] init];
   XCTAssertNotNil(dict);
   XCTAssertEqual(dict.count, 0U);
   XCTAssertNil([dict objectForKey:YES]);
-  [dict enumerateKeysAndObjectsUsingBlock:^(BOOL aKey, id aObject, BOOL *stop) {
+  [dict enumerateKeysAndObjectsUsingBlock:^(BOOL aKey, NSString* aObject, BOOL *stop) {
     #pragma unused(aKey, aObject, stop)
     XCTFail(@"Shouldn't get here!");
   }];
@@ -2170,12 +2170,12 @@
 }
 
 - (void)testOne {
-  GPBBoolObjectDictionary *dict = [GPBBoolObjectDictionary dictionaryWithObject:@"abc" forKey:YES];
+  GPBBoolObjectDictionary<NSString*> *dict = [GPBBoolObjectDictionary dictionaryWithObject:@"abc" forKey:YES];
   XCTAssertNotNil(dict);
   XCTAssertEqual(dict.count, 1U);
   XCTAssertEqualObjects([dict objectForKey:YES], @"abc");
   XCTAssertNil([dict objectForKey:NO]);
-  [dict enumerateKeysAndObjectsUsingBlock:^(BOOL aKey, id aObject, BOOL *stop) {
+  [dict enumerateKeysAndObjectsUsingBlock:^(BOOL aKey, NSString* aObject, BOOL *stop) {
     XCTAssertEqual(aKey, YES);
     XCTAssertEqualObjects(aObject, @"abc");
     XCTAssertNotEqual(stop, NULL);
@@ -2184,8 +2184,8 @@
 
 - (void)testBasics {
   const BOOL kKeys[] = { YES, NO };
-  const id kObjects[] = { @"abc", @"def" };
-  GPBBoolObjectDictionary *dict =
+  const NSString* kObjects[] = { @"abc", @"def" };
+  GPBBoolObjectDictionary<NSString*> *dict =
       [[GPBBoolObjectDictionary alloc] initWithObjects:kObjects
                                                forKeys:kKeys
                                                  count:GPBARRAYSIZE(kObjects)];
@@ -2196,8 +2196,8 @@
 
   __block NSUInteger idx = 0;
   BOOL *seenKeys = malloc(2 * sizeof(BOOL));
-  id *seenObjects = malloc(2 * sizeof(id));
-  [dict enumerateKeysAndObjectsUsingBlock:^(BOOL aKey, id aObject, BOOL *stop) {
+  NSString* *seenObjects = malloc(2 * sizeof(NSString*));
+  [dict enumerateKeysAndObjectsUsingBlock:^(BOOL aKey, NSString* aObject, BOOL *stop) {
     XCTAssertLessThan(idx, 2U);
     seenKeys[idx] = aKey;
     seenObjects[idx] = aObject;
@@ -2219,7 +2219,7 @@
 
   // Stopping the enumeration.
   idx = 0;
-  [dict enumerateKeysAndObjectsUsingBlock:^(BOOL aKey, id aObject, BOOL *stop) {
+  [dict enumerateKeysAndObjectsUsingBlock:^(BOOL aKey, NSString* aObject, BOOL *stop) {
     #pragma unused(aKey, aObject)
     if (idx == 0) *stop = YES;
     XCTAssertNotEqual(idx, 2U);
@@ -2231,30 +2231,30 @@
 - (void)testEquality {
   const BOOL kKeys1[] = { YES, NO };
   const BOOL kKeys2[] = { NO, YES };
-  const id kObjects1[] = { @"abc", @"def" };
-  const id kObjects2[] = { @"def", @"abc" };
-  const id kObjects3[] = { @"def" };
-  GPBBoolObjectDictionary *dict1 =
+  const NSString* kObjects1[] = { @"abc", @"def" };
+  const NSString* kObjects2[] = { @"def", @"abc" };
+  const NSString* kObjects3[] = { @"def" };
+  GPBBoolObjectDictionary<NSString*> *dict1 =
       [[GPBBoolObjectDictionary alloc] initWithObjects:kObjects1
                                                forKeys:kKeys1
                                                  count:GPBARRAYSIZE(kObjects1)];
   XCTAssertNotNil(dict1);
-  GPBBoolObjectDictionary *dict1prime =
+  GPBBoolObjectDictionary<NSString*> *dict1prime =
       [[GPBBoolObjectDictionary alloc] initWithObjects:kObjects1
                                                forKeys:kKeys1
                                                  count:GPBARRAYSIZE(kObjects1)];
   XCTAssertNotNil(dict1prime);
-  GPBBoolObjectDictionary *dict2 =
+  GPBBoolObjectDictionary<NSString*> *dict2 =
       [[GPBBoolObjectDictionary alloc] initWithObjects:kObjects2
                                                forKeys:kKeys1
                                                  count:GPBARRAYSIZE(kObjects2)];
   XCTAssertNotNil(dict2);
-  GPBBoolObjectDictionary *dict3 =
+  GPBBoolObjectDictionary<NSString*> *dict3 =
       [[GPBBoolObjectDictionary alloc] initWithObjects:kObjects1
                                                forKeys:kKeys2
                                                  count:GPBARRAYSIZE(kObjects1)];
   XCTAssertNotNil(dict3);
-  GPBBoolObjectDictionary *dict4 =
+  GPBBoolObjectDictionary<NSString*> *dict4 =
       [[GPBBoolObjectDictionary alloc] initWithObjects:kObjects3
                                                forKeys:kKeys1
                                                  count:GPBARRAYSIZE(kObjects3)];
@@ -2284,14 +2284,14 @@
 
 - (void)testCopy {
   const BOOL kKeys[] = { YES, NO };
-  const id kObjects[] = { @"abc", @"def" };
-  GPBBoolObjectDictionary *dict =
+  const NSString* kObjects[] = { @"abc", @"def" };
+  GPBBoolObjectDictionary<NSString*> *dict =
       [[GPBBoolObjectDictionary alloc] initWithObjects:kObjects
                                                forKeys:kKeys
                                                  count:GPBARRAYSIZE(kObjects)];
   XCTAssertNotNil(dict);
 
-  GPBBoolObjectDictionary *dict2 = [dict copy];
+  GPBBoolObjectDictionary<NSString*> *dict2 = [dict copy];
   XCTAssertNotNil(dict2);
 
   // Should be new object but equal.
@@ -2305,14 +2305,14 @@
 
 - (void)testDictionaryFromDictionary {
   const BOOL kKeys[] = { YES, NO };
-  const id kObjects[] = { @"abc", @"def" };
-  GPBBoolObjectDictionary *dict =
+  const NSString* kObjects[] = { @"abc", @"def" };
+  GPBBoolObjectDictionary<NSString*> *dict =
       [[GPBBoolObjectDictionary alloc] initWithObjects:kObjects
                                                forKeys:kKeys
                                                  count:GPBARRAYSIZE(kObjects)];
   XCTAssertNotNil(dict);
 
-  GPBBoolObjectDictionary *dict2 =
+  GPBBoolObjectDictionary<NSString*> *dict2 =
       [GPBBoolObjectDictionary dictionaryWithDictionary:dict];
   XCTAssertNotNil(dict2);
 
@@ -2323,7 +2323,7 @@
 }
 
 - (void)testAdds {
-  GPBBoolObjectDictionary *dict = [GPBBoolObjectDictionary dictionary];
+  GPBBoolObjectDictionary<NSString*> *dict = [GPBBoolObjectDictionary dictionary];
   XCTAssertNotNil(dict);
 
   XCTAssertEqual(dict.count, 0U);
@@ -2331,8 +2331,8 @@
   XCTAssertEqual(dict.count, 1U);
 
   const BOOL kKeys[] = { NO };
-  const id kObjects[] = { @"def" };
-  GPBBoolObjectDictionary *dict2 =
+  const NSString* kObjects[] = { @"def" };
+  GPBBoolObjectDictionary<NSString*> *dict2 =
       [[GPBBoolObjectDictionary alloc] initWithObjects:kObjects
                                                forKeys:kKeys
                                                  count:GPBARRAYSIZE(kObjects)];
@@ -2347,8 +2347,8 @@
 
 - (void)testRemove {
   const BOOL kKeys[] = { YES, NO};
-  const id kObjects[] = { @"abc", @"def" };
-  GPBBoolObjectDictionary *dict =
+  const NSString* kObjects[] = { @"abc", @"def" };
+  GPBBoolObjectDictionary<NSString*> *dict =
       [[GPBBoolObjectDictionary alloc] initWithObjects:kObjects
                                         forKeys:kKeys
                                           count:GPBARRAYSIZE(kObjects)];
@@ -2375,8 +2375,8 @@
 
 - (void)testInplaceMutation {
   const BOOL kKeys[] = { YES, NO };
-  const id kObjects[] = { @"abc", @"def" };
-  GPBBoolObjectDictionary *dict =
+  const NSString* kObjects[] = { @"abc", @"def" };
+  GPBBoolObjectDictionary<NSString*> *dict =
       [[GPBBoolObjectDictionary alloc] initWithObjects:kObjects
                                         forKeys:kKeys
                                           count:GPBARRAYSIZE(kObjects)];
@@ -2396,8 +2396,8 @@
   XCTAssertEqualObjects([dict objectForKey:NO], @"abc");
 
   const BOOL kKeys2[] = { NO, YES };
-  const id kObjects2[] = { @"def", @"abc" };
-  GPBBoolObjectDictionary *dict2 =
+  const NSString* kObjects2[] = { @"def", @"abc" };
+  GPBBoolObjectDictionary<NSString*> *dict2 =
       [[GPBBoolObjectDictionary alloc] initWithObjects:kObjects2
                                                forKeys:kKeys2
                                                  count:GPBARRAYSIZE(kObjects2)];
diff --git a/objectivec/Tests/GPBDictionaryTests+Int32.m b/objectivec/Tests/GPBDictionaryTests+Int32.m
index 21d3f07..54dd2ed 100644
--- a/objectivec/Tests/GPBDictionaryTests+Int32.m
+++ b/objectivec/Tests/GPBDictionaryTests+Int32.m
@@ -3363,11 +3363,11 @@
 @implementation GPBInt32ObjectDictionaryTests
 
 - (void)testEmpty {
-  GPBInt32ObjectDictionary *dict = [[GPBInt32ObjectDictionary alloc] init];
+  GPBInt32ObjectDictionary<NSString*> *dict = [[GPBInt32ObjectDictionary alloc] init];
   XCTAssertNotNil(dict);
   XCTAssertEqual(dict.count, 0U);
   XCTAssertNil([dict objectForKey:11]);
-  [dict enumerateKeysAndObjectsUsingBlock:^(int32_t aKey, id aObject, BOOL *stop) {
+  [dict enumerateKeysAndObjectsUsingBlock:^(int32_t aKey, NSString* aObject, BOOL *stop) {
     #pragma unused(aKey, aObject, stop)
     XCTFail(@"Shouldn't get here!");
   }];
@@ -3375,12 +3375,12 @@
 }
 
 - (void)testOne {
-  GPBInt32ObjectDictionary *dict = [GPBInt32ObjectDictionary dictionaryWithObject:@"abc" forKey:11];
+  GPBInt32ObjectDictionary<NSString*> *dict = [GPBInt32ObjectDictionary dictionaryWithObject:@"abc" forKey:11];
   XCTAssertNotNil(dict);
   XCTAssertEqual(dict.count, 1U);
   XCTAssertEqualObjects([dict objectForKey:11], @"abc");
   XCTAssertNil([dict objectForKey:12]);
-  [dict enumerateKeysAndObjectsUsingBlock:^(int32_t aKey, id aObject, BOOL *stop) {
+  [dict enumerateKeysAndObjectsUsingBlock:^(int32_t aKey, NSString* aObject, BOOL *stop) {
     XCTAssertEqual(aKey, 11);
     XCTAssertEqualObjects(aObject, @"abc");
     XCTAssertNotEqual(stop, NULL);
@@ -3389,8 +3389,8 @@
 
 - (void)testBasics {
   const int32_t kKeys[] = { 11, 12, 13 };
-  const id kObjects[] = { @"abc", @"def", @"ghi" };
-  GPBInt32ObjectDictionary *dict =
+  const NSString* kObjects[] = { @"abc", @"def", @"ghi" };
+  GPBInt32ObjectDictionary<NSString*> *dict =
       [[GPBInt32ObjectDictionary alloc] initWithObjects:kObjects
                                                 forKeys:kKeys
                                                   count:GPBARRAYSIZE(kObjects)];
@@ -3403,8 +3403,8 @@
 
   __block NSUInteger idx = 0;
   int32_t *seenKeys = malloc(3 * sizeof(int32_t));
-  id *seenObjects = malloc(3 * sizeof(id));
-  [dict enumerateKeysAndObjectsUsingBlock:^(int32_t aKey, id aObject, BOOL *stop) {
+  NSString* *seenObjects = malloc(3 * sizeof(NSString*));
+  [dict enumerateKeysAndObjectsUsingBlock:^(int32_t aKey, NSString* aObject, BOOL *stop) {
     XCTAssertLessThan(idx, 3U);
     seenKeys[idx] = aKey;
     seenObjects[idx] = aObject;
@@ -3426,7 +3426,7 @@
 
   // Stopping the enumeration.
   idx = 0;
-  [dict enumerateKeysAndObjectsUsingBlock:^(int32_t aKey, id aObject, BOOL *stop) {
+  [dict enumerateKeysAndObjectsUsingBlock:^(int32_t aKey, NSString* aObject, BOOL *stop) {
     #pragma unused(aKey, aObject)
     if (idx == 1) *stop = YES;
     XCTAssertNotEqual(idx, 2U);
@@ -3438,30 +3438,30 @@
 - (void)testEquality {
   const int32_t kKeys1[] = { 11, 12, 13, 14 };
   const int32_t kKeys2[] = { 12, 11, 14 };
-  const id kObjects1[] = { @"abc", @"def", @"ghi" };
-  const id kObjects2[] = { @"abc", @"jkl", @"ghi" };
-  const id kObjects3[] = { @"abc", @"def", @"ghi", @"jkl" };
-  GPBInt32ObjectDictionary *dict1 =
+  const NSString* kObjects1[] = { @"abc", @"def", @"ghi" };
+  const NSString* kObjects2[] = { @"abc", @"jkl", @"ghi" };
+  const NSString* kObjects3[] = { @"abc", @"def", @"ghi", @"jkl" };
+  GPBInt32ObjectDictionary<NSString*> *dict1 =
       [[GPBInt32ObjectDictionary alloc] initWithObjects:kObjects1
                                                 forKeys:kKeys1
                                                   count:GPBARRAYSIZE(kObjects1)];
   XCTAssertNotNil(dict1);
-  GPBInt32ObjectDictionary *dict1prime =
+  GPBInt32ObjectDictionary<NSString*> *dict1prime =
       [[GPBInt32ObjectDictionary alloc] initWithObjects:kObjects1
                                                 forKeys:kKeys1
                                                   count:GPBARRAYSIZE(kObjects1)];
   XCTAssertNotNil(dict1prime);
-  GPBInt32ObjectDictionary *dict2 =
+  GPBInt32ObjectDictionary<NSString*> *dict2 =
       [[GPBInt32ObjectDictionary alloc] initWithObjects:kObjects2
                                                 forKeys:kKeys1
                                                   count:GPBARRAYSIZE(kObjects2)];
   XCTAssertNotNil(dict2);
-  GPBInt32ObjectDictionary *dict3 =
+  GPBInt32ObjectDictionary<NSString*> *dict3 =
       [[GPBInt32ObjectDictionary alloc] initWithObjects:kObjects1
                                                 forKeys:kKeys2
                                                   count:GPBARRAYSIZE(kObjects1)];
   XCTAssertNotNil(dict3);
-  GPBInt32ObjectDictionary *dict4 =
+  GPBInt32ObjectDictionary<NSString*> *dict4 =
       [[GPBInt32ObjectDictionary alloc] initWithObjects:kObjects3
                                                 forKeys:kKeys1
                                                   count:GPBARRAYSIZE(kObjects3)];
@@ -3491,14 +3491,14 @@
 
 - (void)testCopy {
   const int32_t kKeys[] = { 11, 12, 13, 14 };
-  const id kObjects[] = { @"abc", @"def", @"ghi", @"jkl" };
-  GPBInt32ObjectDictionary *dict =
+  const NSString* kObjects[] = { @"abc", @"def", @"ghi", @"jkl" };
+  GPBInt32ObjectDictionary<NSString*> *dict =
       [[GPBInt32ObjectDictionary alloc] initWithObjects:kObjects
                                                 forKeys:kKeys
                                                   count:GPBARRAYSIZE(kObjects)];
   XCTAssertNotNil(dict);
 
-  GPBInt32ObjectDictionary *dict2 = [dict copy];
+  GPBInt32ObjectDictionary<NSString*> *dict2 = [dict copy];
   XCTAssertNotNil(dict2);
 
   // Should be new object but equal.
@@ -3512,14 +3512,14 @@
 
 - (void)testDictionaryFromDictionary {
   const int32_t kKeys[] = { 11, 12, 13, 14 };
-  const id kObjects[] = { @"abc", @"def", @"ghi", @"jkl" };
-  GPBInt32ObjectDictionary *dict =
+  const NSString* kObjects[] = { @"abc", @"def", @"ghi", @"jkl" };
+  GPBInt32ObjectDictionary<NSString*> *dict =
       [[GPBInt32ObjectDictionary alloc] initWithObjects:kObjects
                                                 forKeys:kKeys
                                                   count:GPBARRAYSIZE(kObjects)];
   XCTAssertNotNil(dict);
 
-  GPBInt32ObjectDictionary *dict2 =
+  GPBInt32ObjectDictionary<NSString*> *dict2 =
       [GPBInt32ObjectDictionary dictionaryWithDictionary:dict];
   XCTAssertNotNil(dict2);
 
@@ -3530,7 +3530,7 @@
 }
 
 - (void)testAdds {
-  GPBInt32ObjectDictionary *dict = [GPBInt32ObjectDictionary dictionary];
+  GPBInt32ObjectDictionary<NSString*> *dict = [GPBInt32ObjectDictionary dictionary];
   XCTAssertNotNil(dict);
 
   XCTAssertEqual(dict.count, 0U);
@@ -3538,8 +3538,8 @@
   XCTAssertEqual(dict.count, 1U);
 
   const int32_t kKeys[] = { 12, 13, 14 };
-  const id kObjects[] = { @"def", @"ghi", @"jkl" };
-  GPBInt32ObjectDictionary *dict2 =
+  const NSString* kObjects[] = { @"def", @"ghi", @"jkl" };
+  GPBInt32ObjectDictionary<NSString*> *dict2 =
       [[GPBInt32ObjectDictionary alloc] initWithObjects:kObjects
                                                 forKeys:kKeys
                                                   count:GPBARRAYSIZE(kObjects)];
@@ -3556,8 +3556,8 @@
 
 - (void)testRemove {
   const int32_t kKeys[] = { 11, 12, 13, 14 };
-  const id kObjects[] = { @"abc", @"def", @"ghi", @"jkl" };
-  GPBInt32ObjectDictionary *dict =
+  const NSString* kObjects[] = { @"abc", @"def", @"ghi", @"jkl" };
+  GPBInt32ObjectDictionary<NSString*> *dict =
       [[GPBInt32ObjectDictionary alloc] initWithObjects:kObjects
                                          forKeys:kKeys
                                            count:GPBARRAYSIZE(kObjects)];
@@ -3597,8 +3597,8 @@
 
 - (void)testInplaceMutation {
   const int32_t kKeys[] = { 11, 12, 13, 14 };
-  const id kObjects[] = { @"abc", @"def", @"ghi", @"jkl" };
-  GPBInt32ObjectDictionary *dict =
+  const NSString* kObjects[] = { @"abc", @"def", @"ghi", @"jkl" };
+  GPBInt32ObjectDictionary<NSString*> *dict =
       [[GPBInt32ObjectDictionary alloc] initWithObjects:kObjects
                                          forKeys:kKeys
                                            count:GPBARRAYSIZE(kObjects)];
@@ -3624,8 +3624,8 @@
   XCTAssertEqualObjects([dict objectForKey:14], @"def");
 
   const int32_t kKeys2[] = { 12, 13 };
-  const id kObjects2[] = { @"ghi", @"abc" };
-  GPBInt32ObjectDictionary *dict2 =
+  const NSString* kObjects2[] = { @"ghi", @"abc" };
+  GPBInt32ObjectDictionary<NSString*> *dict2 =
       [[GPBInt32ObjectDictionary alloc] initWithObjects:kObjects2
                                                 forKeys:kKeys2
                                                   count:GPBARRAYSIZE(kObjects2)];
diff --git a/objectivec/Tests/GPBDictionaryTests+Int64.m b/objectivec/Tests/GPBDictionaryTests+Int64.m
index 27f77f2..66bc648 100644
--- a/objectivec/Tests/GPBDictionaryTests+Int64.m
+++ b/objectivec/Tests/GPBDictionaryTests+Int64.m
@@ -3363,11 +3363,11 @@
 @implementation GPBInt64ObjectDictionaryTests
 
 - (void)testEmpty {
-  GPBInt64ObjectDictionary *dict = [[GPBInt64ObjectDictionary alloc] init];
+  GPBInt64ObjectDictionary<NSString*> *dict = [[GPBInt64ObjectDictionary alloc] init];
   XCTAssertNotNil(dict);
   XCTAssertEqual(dict.count, 0U);
   XCTAssertNil([dict objectForKey:21LL]);
-  [dict enumerateKeysAndObjectsUsingBlock:^(int64_t aKey, id aObject, BOOL *stop) {
+  [dict enumerateKeysAndObjectsUsingBlock:^(int64_t aKey, NSString* aObject, BOOL *stop) {
     #pragma unused(aKey, aObject, stop)
     XCTFail(@"Shouldn't get here!");
   }];
@@ -3375,12 +3375,12 @@
 }
 
 - (void)testOne {
-  GPBInt64ObjectDictionary *dict = [GPBInt64ObjectDictionary dictionaryWithObject:@"abc" forKey:21LL];
+  GPBInt64ObjectDictionary<NSString*> *dict = [GPBInt64ObjectDictionary dictionaryWithObject:@"abc" forKey:21LL];
   XCTAssertNotNil(dict);
   XCTAssertEqual(dict.count, 1U);
   XCTAssertEqualObjects([dict objectForKey:21LL], @"abc");
   XCTAssertNil([dict objectForKey:22LL]);
-  [dict enumerateKeysAndObjectsUsingBlock:^(int64_t aKey, id aObject, BOOL *stop) {
+  [dict enumerateKeysAndObjectsUsingBlock:^(int64_t aKey, NSString* aObject, BOOL *stop) {
     XCTAssertEqual(aKey, 21LL);
     XCTAssertEqualObjects(aObject, @"abc");
     XCTAssertNotEqual(stop, NULL);
@@ -3389,8 +3389,8 @@
 
 - (void)testBasics {
   const int64_t kKeys[] = { 21LL, 22LL, 23LL };
-  const id kObjects[] = { @"abc", @"def", @"ghi" };
-  GPBInt64ObjectDictionary *dict =
+  const NSString* kObjects[] = { @"abc", @"def", @"ghi" };
+  GPBInt64ObjectDictionary<NSString*> *dict =
       [[GPBInt64ObjectDictionary alloc] initWithObjects:kObjects
                                                 forKeys:kKeys
                                                   count:GPBARRAYSIZE(kObjects)];
@@ -3403,8 +3403,8 @@
 
   __block NSUInteger idx = 0;
   int64_t *seenKeys = malloc(3 * sizeof(int64_t));
-  id *seenObjects = malloc(3 * sizeof(id));
-  [dict enumerateKeysAndObjectsUsingBlock:^(int64_t aKey, id aObject, BOOL *stop) {
+  NSString* *seenObjects = malloc(3 * sizeof(NSString*));
+  [dict enumerateKeysAndObjectsUsingBlock:^(int64_t aKey, NSString* aObject, BOOL *stop) {
     XCTAssertLessThan(idx, 3U);
     seenKeys[idx] = aKey;
     seenObjects[idx] = aObject;
@@ -3426,7 +3426,7 @@
 
   // Stopping the enumeration.
   idx = 0;
-  [dict enumerateKeysAndObjectsUsingBlock:^(int64_t aKey, id aObject, BOOL *stop) {
+  [dict enumerateKeysAndObjectsUsingBlock:^(int64_t aKey, NSString* aObject, BOOL *stop) {
     #pragma unused(aKey, aObject)
     if (idx == 1) *stop = YES;
     XCTAssertNotEqual(idx, 2U);
@@ -3438,30 +3438,30 @@
 - (void)testEquality {
   const int64_t kKeys1[] = { 21LL, 22LL, 23LL, 24LL };
   const int64_t kKeys2[] = { 22LL, 21LL, 24LL };
-  const id kObjects1[] = { @"abc", @"def", @"ghi" };
-  const id kObjects2[] = { @"abc", @"jkl", @"ghi" };
-  const id kObjects3[] = { @"abc", @"def", @"ghi", @"jkl" };
-  GPBInt64ObjectDictionary *dict1 =
+  const NSString* kObjects1[] = { @"abc", @"def", @"ghi" };
+  const NSString* kObjects2[] = { @"abc", @"jkl", @"ghi" };
+  const NSString* kObjects3[] = { @"abc", @"def", @"ghi", @"jkl" };
+  GPBInt64ObjectDictionary<NSString*> *dict1 =
       [[GPBInt64ObjectDictionary alloc] initWithObjects:kObjects1
                                                 forKeys:kKeys1
                                                   count:GPBARRAYSIZE(kObjects1)];
   XCTAssertNotNil(dict1);
-  GPBInt64ObjectDictionary *dict1prime =
+  GPBInt64ObjectDictionary<NSString*> *dict1prime =
       [[GPBInt64ObjectDictionary alloc] initWithObjects:kObjects1
                                                 forKeys:kKeys1
                                                   count:GPBARRAYSIZE(kObjects1)];
   XCTAssertNotNil(dict1prime);
-  GPBInt64ObjectDictionary *dict2 =
+  GPBInt64ObjectDictionary<NSString*> *dict2 =
       [[GPBInt64ObjectDictionary alloc] initWithObjects:kObjects2
                                                 forKeys:kKeys1
                                                   count:GPBARRAYSIZE(kObjects2)];
   XCTAssertNotNil(dict2);
-  GPBInt64ObjectDictionary *dict3 =
+  GPBInt64ObjectDictionary<NSString*> *dict3 =
       [[GPBInt64ObjectDictionary alloc] initWithObjects:kObjects1
                                                 forKeys:kKeys2
                                                   count:GPBARRAYSIZE(kObjects1)];
   XCTAssertNotNil(dict3);
-  GPBInt64ObjectDictionary *dict4 =
+  GPBInt64ObjectDictionary<NSString*> *dict4 =
       [[GPBInt64ObjectDictionary alloc] initWithObjects:kObjects3
                                                 forKeys:kKeys1
                                                   count:GPBARRAYSIZE(kObjects3)];
@@ -3491,14 +3491,14 @@
 
 - (void)testCopy {
   const int64_t kKeys[] = { 21LL, 22LL, 23LL, 24LL };
-  const id kObjects[] = { @"abc", @"def", @"ghi", @"jkl" };
-  GPBInt64ObjectDictionary *dict =
+  const NSString* kObjects[] = { @"abc", @"def", @"ghi", @"jkl" };
+  GPBInt64ObjectDictionary<NSString*> *dict =
       [[GPBInt64ObjectDictionary alloc] initWithObjects:kObjects
                                                 forKeys:kKeys
                                                   count:GPBARRAYSIZE(kObjects)];
   XCTAssertNotNil(dict);
 
-  GPBInt64ObjectDictionary *dict2 = [dict copy];
+  GPBInt64ObjectDictionary<NSString*> *dict2 = [dict copy];
   XCTAssertNotNil(dict2);
 
   // Should be new object but equal.
@@ -3512,14 +3512,14 @@
 
 - (void)testDictionaryFromDictionary {
   const int64_t kKeys[] = { 21LL, 22LL, 23LL, 24LL };
-  const id kObjects[] = { @"abc", @"def", @"ghi", @"jkl" };
-  GPBInt64ObjectDictionary *dict =
+  const NSString* kObjects[] = { @"abc", @"def", @"ghi", @"jkl" };
+  GPBInt64ObjectDictionary<NSString*> *dict =
       [[GPBInt64ObjectDictionary alloc] initWithObjects:kObjects
                                                 forKeys:kKeys
                                                   count:GPBARRAYSIZE(kObjects)];
   XCTAssertNotNil(dict);
 
-  GPBInt64ObjectDictionary *dict2 =
+  GPBInt64ObjectDictionary<NSString*> *dict2 =
       [GPBInt64ObjectDictionary dictionaryWithDictionary:dict];
   XCTAssertNotNil(dict2);
 
@@ -3530,7 +3530,7 @@
 }
 
 - (void)testAdds {
-  GPBInt64ObjectDictionary *dict = [GPBInt64ObjectDictionary dictionary];
+  GPBInt64ObjectDictionary<NSString*> *dict = [GPBInt64ObjectDictionary dictionary];
   XCTAssertNotNil(dict);
 
   XCTAssertEqual(dict.count, 0U);
@@ -3538,8 +3538,8 @@
   XCTAssertEqual(dict.count, 1U);
 
   const int64_t kKeys[] = { 22LL, 23LL, 24LL };
-  const id kObjects[] = { @"def", @"ghi", @"jkl" };
-  GPBInt64ObjectDictionary *dict2 =
+  const NSString* kObjects[] = { @"def", @"ghi", @"jkl" };
+  GPBInt64ObjectDictionary<NSString*> *dict2 =
       [[GPBInt64ObjectDictionary alloc] initWithObjects:kObjects
                                                 forKeys:kKeys
                                                   count:GPBARRAYSIZE(kObjects)];
@@ -3556,8 +3556,8 @@
 
 - (void)testRemove {
   const int64_t kKeys[] = { 21LL, 22LL, 23LL, 24LL };
-  const id kObjects[] = { @"abc", @"def", @"ghi", @"jkl" };
-  GPBInt64ObjectDictionary *dict =
+  const NSString* kObjects[] = { @"abc", @"def", @"ghi", @"jkl" };
+  GPBInt64ObjectDictionary<NSString*> *dict =
       [[GPBInt64ObjectDictionary alloc] initWithObjects:kObjects
                                          forKeys:kKeys
                                            count:GPBARRAYSIZE(kObjects)];
@@ -3597,8 +3597,8 @@
 
 - (void)testInplaceMutation {
   const int64_t kKeys[] = { 21LL, 22LL, 23LL, 24LL };
-  const id kObjects[] = { @"abc", @"def", @"ghi", @"jkl" };
-  GPBInt64ObjectDictionary *dict =
+  const NSString* kObjects[] = { @"abc", @"def", @"ghi", @"jkl" };
+  GPBInt64ObjectDictionary<NSString*> *dict =
       [[GPBInt64ObjectDictionary alloc] initWithObjects:kObjects
                                          forKeys:kKeys
                                            count:GPBARRAYSIZE(kObjects)];
@@ -3624,8 +3624,8 @@
   XCTAssertEqualObjects([dict objectForKey:24LL], @"def");
 
   const int64_t kKeys2[] = { 22LL, 23LL };
-  const id kObjects2[] = { @"ghi", @"abc" };
-  GPBInt64ObjectDictionary *dict2 =
+  const NSString* kObjects2[] = { @"ghi", @"abc" };
+  GPBInt64ObjectDictionary<NSString*> *dict2 =
       [[GPBInt64ObjectDictionary alloc] initWithObjects:kObjects2
                                                 forKeys:kKeys2
                                                   count:GPBARRAYSIZE(kObjects2)];
diff --git a/objectivec/Tests/GPBDictionaryTests+UInt32.m b/objectivec/Tests/GPBDictionaryTests+UInt32.m
index c7c5765..499f2ad 100644
--- a/objectivec/Tests/GPBDictionaryTests+UInt32.m
+++ b/objectivec/Tests/GPBDictionaryTests+UInt32.m
@@ -3363,11 +3363,11 @@
 @implementation GPBUInt32ObjectDictionaryTests
 
 - (void)testEmpty {
-  GPBUInt32ObjectDictionary *dict = [[GPBUInt32ObjectDictionary alloc] init];
+  GPBUInt32ObjectDictionary<NSString*> *dict = [[GPBUInt32ObjectDictionary alloc] init];
   XCTAssertNotNil(dict);
   XCTAssertEqual(dict.count, 0U);
   XCTAssertNil([dict objectForKey:1U]);
-  [dict enumerateKeysAndObjectsUsingBlock:^(uint32_t aKey, id aObject, BOOL *stop) {
+  [dict enumerateKeysAndObjectsUsingBlock:^(uint32_t aKey, NSString* aObject, BOOL *stop) {
     #pragma unused(aKey, aObject, stop)
     XCTFail(@"Shouldn't get here!");
   }];
@@ -3375,12 +3375,12 @@
 }
 
 - (void)testOne {
-  GPBUInt32ObjectDictionary *dict = [GPBUInt32ObjectDictionary dictionaryWithObject:@"abc" forKey:1U];
+  GPBUInt32ObjectDictionary<NSString*> *dict = [GPBUInt32ObjectDictionary dictionaryWithObject:@"abc" forKey:1U];
   XCTAssertNotNil(dict);
   XCTAssertEqual(dict.count, 1U);
   XCTAssertEqualObjects([dict objectForKey:1U], @"abc");
   XCTAssertNil([dict objectForKey:2U]);
-  [dict enumerateKeysAndObjectsUsingBlock:^(uint32_t aKey, id aObject, BOOL *stop) {
+  [dict enumerateKeysAndObjectsUsingBlock:^(uint32_t aKey, NSString* aObject, BOOL *stop) {
     XCTAssertEqual(aKey, 1U);
     XCTAssertEqualObjects(aObject, @"abc");
     XCTAssertNotEqual(stop, NULL);
@@ -3389,8 +3389,8 @@
 
 - (void)testBasics {
   const uint32_t kKeys[] = { 1U, 2U, 3U };
-  const id kObjects[] = { @"abc", @"def", @"ghi" };
-  GPBUInt32ObjectDictionary *dict =
+  const NSString* kObjects[] = { @"abc", @"def", @"ghi" };
+  GPBUInt32ObjectDictionary<NSString*> *dict =
       [[GPBUInt32ObjectDictionary alloc] initWithObjects:kObjects
                                                  forKeys:kKeys
                                                    count:GPBARRAYSIZE(kObjects)];
@@ -3403,8 +3403,8 @@
 
   __block NSUInteger idx = 0;
   uint32_t *seenKeys = malloc(3 * sizeof(uint32_t));
-  id *seenObjects = malloc(3 * sizeof(id));
-  [dict enumerateKeysAndObjectsUsingBlock:^(uint32_t aKey, id aObject, BOOL *stop) {
+  NSString* *seenObjects = malloc(3 * sizeof(NSString*));
+  [dict enumerateKeysAndObjectsUsingBlock:^(uint32_t aKey, NSString* aObject, BOOL *stop) {
     XCTAssertLessThan(idx, 3U);
     seenKeys[idx] = aKey;
     seenObjects[idx] = aObject;
@@ -3426,7 +3426,7 @@
 
   // Stopping the enumeration.
   idx = 0;
-  [dict enumerateKeysAndObjectsUsingBlock:^(uint32_t aKey, id aObject, BOOL *stop) {
+  [dict enumerateKeysAndObjectsUsingBlock:^(uint32_t aKey, NSString* aObject, BOOL *stop) {
     #pragma unused(aKey, aObject)
     if (idx == 1) *stop = YES;
     XCTAssertNotEqual(idx, 2U);
@@ -3438,30 +3438,30 @@
 - (void)testEquality {
   const uint32_t kKeys1[] = { 1U, 2U, 3U, 4U };
   const uint32_t kKeys2[] = { 2U, 1U, 4U };
-  const id kObjects1[] = { @"abc", @"def", @"ghi" };
-  const id kObjects2[] = { @"abc", @"jkl", @"ghi" };
-  const id kObjects3[] = { @"abc", @"def", @"ghi", @"jkl" };
-  GPBUInt32ObjectDictionary *dict1 =
+  const NSString* kObjects1[] = { @"abc", @"def", @"ghi" };
+  const NSString* kObjects2[] = { @"abc", @"jkl", @"ghi" };
+  const NSString* kObjects3[] = { @"abc", @"def", @"ghi", @"jkl" };
+  GPBUInt32ObjectDictionary<NSString*> *dict1 =
       [[GPBUInt32ObjectDictionary alloc] initWithObjects:kObjects1
                                                  forKeys:kKeys1
                                                    count:GPBARRAYSIZE(kObjects1)];
   XCTAssertNotNil(dict1);
-  GPBUInt32ObjectDictionary *dict1prime =
+  GPBUInt32ObjectDictionary<NSString*> *dict1prime =
       [[GPBUInt32ObjectDictionary alloc] initWithObjects:kObjects1
                                                  forKeys:kKeys1
                                                    count:GPBARRAYSIZE(kObjects1)];
   XCTAssertNotNil(dict1prime);
-  GPBUInt32ObjectDictionary *dict2 =
+  GPBUInt32ObjectDictionary<NSString*> *dict2 =
       [[GPBUInt32ObjectDictionary alloc] initWithObjects:kObjects2
                                                  forKeys:kKeys1
                                                    count:GPBARRAYSIZE(kObjects2)];
   XCTAssertNotNil(dict2);
-  GPBUInt32ObjectDictionary *dict3 =
+  GPBUInt32ObjectDictionary<NSString*> *dict3 =
       [[GPBUInt32ObjectDictionary alloc] initWithObjects:kObjects1
                                                  forKeys:kKeys2
                                                    count:GPBARRAYSIZE(kObjects1)];
   XCTAssertNotNil(dict3);
-  GPBUInt32ObjectDictionary *dict4 =
+  GPBUInt32ObjectDictionary<NSString*> *dict4 =
       [[GPBUInt32ObjectDictionary alloc] initWithObjects:kObjects3
                                                  forKeys:kKeys1
                                                    count:GPBARRAYSIZE(kObjects3)];
@@ -3491,14 +3491,14 @@
 
 - (void)testCopy {
   const uint32_t kKeys[] = { 1U, 2U, 3U, 4U };
-  const id kObjects[] = { @"abc", @"def", @"ghi", @"jkl" };
-  GPBUInt32ObjectDictionary *dict =
+  const NSString* kObjects[] = { @"abc", @"def", @"ghi", @"jkl" };
+  GPBUInt32ObjectDictionary<NSString*> *dict =
       [[GPBUInt32ObjectDictionary alloc] initWithObjects:kObjects
                                                  forKeys:kKeys
                                                    count:GPBARRAYSIZE(kObjects)];
   XCTAssertNotNil(dict);
 
-  GPBUInt32ObjectDictionary *dict2 = [dict copy];
+  GPBUInt32ObjectDictionary<NSString*> *dict2 = [dict copy];
   XCTAssertNotNil(dict2);
 
   // Should be new object but equal.
@@ -3512,14 +3512,14 @@
 
 - (void)testDictionaryFromDictionary {
   const uint32_t kKeys[] = { 1U, 2U, 3U, 4U };
-  const id kObjects[] = { @"abc", @"def", @"ghi", @"jkl" };
-  GPBUInt32ObjectDictionary *dict =
+  const NSString* kObjects[] = { @"abc", @"def", @"ghi", @"jkl" };
+  GPBUInt32ObjectDictionary<NSString*> *dict =
       [[GPBUInt32ObjectDictionary alloc] initWithObjects:kObjects
                                                  forKeys:kKeys
                                                    count:GPBARRAYSIZE(kObjects)];
   XCTAssertNotNil(dict);
 
-  GPBUInt32ObjectDictionary *dict2 =
+  GPBUInt32ObjectDictionary<NSString*> *dict2 =
       [GPBUInt32ObjectDictionary dictionaryWithDictionary:dict];
   XCTAssertNotNil(dict2);
 
@@ -3530,7 +3530,7 @@
 }
 
 - (void)testAdds {
-  GPBUInt32ObjectDictionary *dict = [GPBUInt32ObjectDictionary dictionary];
+  GPBUInt32ObjectDictionary<NSString*> *dict = [GPBUInt32ObjectDictionary dictionary];
   XCTAssertNotNil(dict);
 
   XCTAssertEqual(dict.count, 0U);
@@ -3538,8 +3538,8 @@
   XCTAssertEqual(dict.count, 1U);
 
   const uint32_t kKeys[] = { 2U, 3U, 4U };
-  const id kObjects[] = { @"def", @"ghi", @"jkl" };
-  GPBUInt32ObjectDictionary *dict2 =
+  const NSString* kObjects[] = { @"def", @"ghi", @"jkl" };
+  GPBUInt32ObjectDictionary<NSString*> *dict2 =
       [[GPBUInt32ObjectDictionary alloc] initWithObjects:kObjects
                                                  forKeys:kKeys
                                                    count:GPBARRAYSIZE(kObjects)];
@@ -3556,8 +3556,8 @@
 
 - (void)testRemove {
   const uint32_t kKeys[] = { 1U, 2U, 3U, 4U };
-  const id kObjects[] = { @"abc", @"def", @"ghi", @"jkl" };
-  GPBUInt32ObjectDictionary *dict =
+  const NSString* kObjects[] = { @"abc", @"def", @"ghi", @"jkl" };
+  GPBUInt32ObjectDictionary<NSString*> *dict =
       [[GPBUInt32ObjectDictionary alloc] initWithObjects:kObjects
                                           forKeys:kKeys
                                             count:GPBARRAYSIZE(kObjects)];
@@ -3597,8 +3597,8 @@
 
 - (void)testInplaceMutation {
   const uint32_t kKeys[] = { 1U, 2U, 3U, 4U };
-  const id kObjects[] = { @"abc", @"def", @"ghi", @"jkl" };
-  GPBUInt32ObjectDictionary *dict =
+  const NSString* kObjects[] = { @"abc", @"def", @"ghi", @"jkl" };
+  GPBUInt32ObjectDictionary<NSString*> *dict =
       [[GPBUInt32ObjectDictionary alloc] initWithObjects:kObjects
                                           forKeys:kKeys
                                             count:GPBARRAYSIZE(kObjects)];
@@ -3624,8 +3624,8 @@
   XCTAssertEqualObjects([dict objectForKey:4U], @"def");
 
   const uint32_t kKeys2[] = { 2U, 3U };
-  const id kObjects2[] = { @"ghi", @"abc" };
-  GPBUInt32ObjectDictionary *dict2 =
+  const NSString* kObjects2[] = { @"ghi", @"abc" };
+  GPBUInt32ObjectDictionary<NSString*> *dict2 =
       [[GPBUInt32ObjectDictionary alloc] initWithObjects:kObjects2
                                                  forKeys:kKeys2
                                                    count:GPBARRAYSIZE(kObjects2)];
diff --git a/objectivec/Tests/GPBDictionaryTests+UInt64.m b/objectivec/Tests/GPBDictionaryTests+UInt64.m
index b64d3a9..327e154 100644
--- a/objectivec/Tests/GPBDictionaryTests+UInt64.m
+++ b/objectivec/Tests/GPBDictionaryTests+UInt64.m
@@ -3363,11 +3363,11 @@
 @implementation GPBUInt64ObjectDictionaryTests
 
 - (void)testEmpty {
-  GPBUInt64ObjectDictionary *dict = [[GPBUInt64ObjectDictionary alloc] init];
+  GPBUInt64ObjectDictionary<NSString*> *dict = [[GPBUInt64ObjectDictionary alloc] init];
   XCTAssertNotNil(dict);
   XCTAssertEqual(dict.count, 0U);
   XCTAssertNil([dict objectForKey:31ULL]);
-  [dict enumerateKeysAndObjectsUsingBlock:^(uint64_t aKey, id aObject, BOOL *stop) {
+  [dict enumerateKeysAndObjectsUsingBlock:^(uint64_t aKey, NSString* aObject, BOOL *stop) {
     #pragma unused(aKey, aObject, stop)
     XCTFail(@"Shouldn't get here!");
   }];
@@ -3375,12 +3375,12 @@
 }
 
 - (void)testOne {
-  GPBUInt64ObjectDictionary *dict = [GPBUInt64ObjectDictionary dictionaryWithObject:@"abc" forKey:31ULL];
+  GPBUInt64ObjectDictionary<NSString*> *dict = [GPBUInt64ObjectDictionary dictionaryWithObject:@"abc" forKey:31ULL];
   XCTAssertNotNil(dict);
   XCTAssertEqual(dict.count, 1U);
   XCTAssertEqualObjects([dict objectForKey:31ULL], @"abc");
   XCTAssertNil([dict objectForKey:32ULL]);
-  [dict enumerateKeysAndObjectsUsingBlock:^(uint64_t aKey, id aObject, BOOL *stop) {
+  [dict enumerateKeysAndObjectsUsingBlock:^(uint64_t aKey, NSString* aObject, BOOL *stop) {
     XCTAssertEqual(aKey, 31ULL);
     XCTAssertEqualObjects(aObject, @"abc");
     XCTAssertNotEqual(stop, NULL);
@@ -3389,8 +3389,8 @@
 
 - (void)testBasics {
   const uint64_t kKeys[] = { 31ULL, 32ULL, 33ULL };
-  const id kObjects[] = { @"abc", @"def", @"ghi" };
-  GPBUInt64ObjectDictionary *dict =
+  const NSString* kObjects[] = { @"abc", @"def", @"ghi" };
+  GPBUInt64ObjectDictionary<NSString*> *dict =
       [[GPBUInt64ObjectDictionary alloc] initWithObjects:kObjects
                                                  forKeys:kKeys
                                                    count:GPBARRAYSIZE(kObjects)];
@@ -3403,8 +3403,8 @@
 
   __block NSUInteger idx = 0;
   uint64_t *seenKeys = malloc(3 * sizeof(uint64_t));
-  id *seenObjects = malloc(3 * sizeof(id));
-  [dict enumerateKeysAndObjectsUsingBlock:^(uint64_t aKey, id aObject, BOOL *stop) {
+  NSString* *seenObjects = malloc(3 * sizeof(NSString*));
+  [dict enumerateKeysAndObjectsUsingBlock:^(uint64_t aKey, NSString* aObject, BOOL *stop) {
     XCTAssertLessThan(idx, 3U);
     seenKeys[idx] = aKey;
     seenObjects[idx] = aObject;
@@ -3426,7 +3426,7 @@
 
   // Stopping the enumeration.
   idx = 0;
-  [dict enumerateKeysAndObjectsUsingBlock:^(uint64_t aKey, id aObject, BOOL *stop) {
+  [dict enumerateKeysAndObjectsUsingBlock:^(uint64_t aKey, NSString* aObject, BOOL *stop) {
     #pragma unused(aKey, aObject)
     if (idx == 1) *stop = YES;
     XCTAssertNotEqual(idx, 2U);
@@ -3438,30 +3438,30 @@
 - (void)testEquality {
   const uint64_t kKeys1[] = { 31ULL, 32ULL, 33ULL, 34ULL };
   const uint64_t kKeys2[] = { 32ULL, 31ULL, 34ULL };
-  const id kObjects1[] = { @"abc", @"def", @"ghi" };
-  const id kObjects2[] = { @"abc", @"jkl", @"ghi" };
-  const id kObjects3[] = { @"abc", @"def", @"ghi", @"jkl" };
-  GPBUInt64ObjectDictionary *dict1 =
+  const NSString* kObjects1[] = { @"abc", @"def", @"ghi" };
+  const NSString* kObjects2[] = { @"abc", @"jkl", @"ghi" };
+  const NSString* kObjects3[] = { @"abc", @"def", @"ghi", @"jkl" };
+  GPBUInt64ObjectDictionary<NSString*> *dict1 =
       [[GPBUInt64ObjectDictionary alloc] initWithObjects:kObjects1
                                                  forKeys:kKeys1
                                                    count:GPBARRAYSIZE(kObjects1)];
   XCTAssertNotNil(dict1);
-  GPBUInt64ObjectDictionary *dict1prime =
+  GPBUInt64ObjectDictionary<NSString*> *dict1prime =
       [[GPBUInt64ObjectDictionary alloc] initWithObjects:kObjects1
                                                  forKeys:kKeys1
                                                    count:GPBARRAYSIZE(kObjects1)];
   XCTAssertNotNil(dict1prime);
-  GPBUInt64ObjectDictionary *dict2 =
+  GPBUInt64ObjectDictionary<NSString*> *dict2 =
       [[GPBUInt64ObjectDictionary alloc] initWithObjects:kObjects2
                                                  forKeys:kKeys1
                                                    count:GPBARRAYSIZE(kObjects2)];
   XCTAssertNotNil(dict2);
-  GPBUInt64ObjectDictionary *dict3 =
+  GPBUInt64ObjectDictionary<NSString*> *dict3 =
       [[GPBUInt64ObjectDictionary alloc] initWithObjects:kObjects1
                                                  forKeys:kKeys2
                                                    count:GPBARRAYSIZE(kObjects1)];
   XCTAssertNotNil(dict3);
-  GPBUInt64ObjectDictionary *dict4 =
+  GPBUInt64ObjectDictionary<NSString*> *dict4 =
       [[GPBUInt64ObjectDictionary alloc] initWithObjects:kObjects3
                                                  forKeys:kKeys1
                                                    count:GPBARRAYSIZE(kObjects3)];
@@ -3491,14 +3491,14 @@
 
 - (void)testCopy {
   const uint64_t kKeys[] = { 31ULL, 32ULL, 33ULL, 34ULL };
-  const id kObjects[] = { @"abc", @"def", @"ghi", @"jkl" };
-  GPBUInt64ObjectDictionary *dict =
+  const NSString* kObjects[] = { @"abc", @"def", @"ghi", @"jkl" };
+  GPBUInt64ObjectDictionary<NSString*> *dict =
       [[GPBUInt64ObjectDictionary alloc] initWithObjects:kObjects
                                                  forKeys:kKeys
                                                    count:GPBARRAYSIZE(kObjects)];
   XCTAssertNotNil(dict);
 
-  GPBUInt64ObjectDictionary *dict2 = [dict copy];
+  GPBUInt64ObjectDictionary<NSString*> *dict2 = [dict copy];
   XCTAssertNotNil(dict2);
 
   // Should be new object but equal.
@@ -3512,14 +3512,14 @@
 
 - (void)testDictionaryFromDictionary {
   const uint64_t kKeys[] = { 31ULL, 32ULL, 33ULL, 34ULL };
-  const id kObjects[] = { @"abc", @"def", @"ghi", @"jkl" };
-  GPBUInt64ObjectDictionary *dict =
+  const NSString* kObjects[] = { @"abc", @"def", @"ghi", @"jkl" };
+  GPBUInt64ObjectDictionary<NSString*> *dict =
       [[GPBUInt64ObjectDictionary alloc] initWithObjects:kObjects
                                                  forKeys:kKeys
                                                    count:GPBARRAYSIZE(kObjects)];
   XCTAssertNotNil(dict);
 
-  GPBUInt64ObjectDictionary *dict2 =
+  GPBUInt64ObjectDictionary<NSString*> *dict2 =
       [GPBUInt64ObjectDictionary dictionaryWithDictionary:dict];
   XCTAssertNotNil(dict2);
 
@@ -3530,7 +3530,7 @@
 }
 
 - (void)testAdds {
-  GPBUInt64ObjectDictionary *dict = [GPBUInt64ObjectDictionary dictionary];
+  GPBUInt64ObjectDictionary<NSString*> *dict = [GPBUInt64ObjectDictionary dictionary];
   XCTAssertNotNil(dict);
 
   XCTAssertEqual(dict.count, 0U);
@@ -3538,8 +3538,8 @@
   XCTAssertEqual(dict.count, 1U);
 
   const uint64_t kKeys[] = { 32ULL, 33ULL, 34ULL };
-  const id kObjects[] = { @"def", @"ghi", @"jkl" };
-  GPBUInt64ObjectDictionary *dict2 =
+  const NSString* kObjects[] = { @"def", @"ghi", @"jkl" };
+  GPBUInt64ObjectDictionary<NSString*> *dict2 =
       [[GPBUInt64ObjectDictionary alloc] initWithObjects:kObjects
                                                  forKeys:kKeys
                                                    count:GPBARRAYSIZE(kObjects)];
@@ -3556,8 +3556,8 @@
 
 - (void)testRemove {
   const uint64_t kKeys[] = { 31ULL, 32ULL, 33ULL, 34ULL };
-  const id kObjects[] = { @"abc", @"def", @"ghi", @"jkl" };
-  GPBUInt64ObjectDictionary *dict =
+  const NSString* kObjects[] = { @"abc", @"def", @"ghi", @"jkl" };
+  GPBUInt64ObjectDictionary<NSString*> *dict =
       [[GPBUInt64ObjectDictionary alloc] initWithObjects:kObjects
                                           forKeys:kKeys
                                             count:GPBARRAYSIZE(kObjects)];
@@ -3597,8 +3597,8 @@
 
 - (void)testInplaceMutation {
   const uint64_t kKeys[] = { 31ULL, 32ULL, 33ULL, 34ULL };
-  const id kObjects[] = { @"abc", @"def", @"ghi", @"jkl" };
-  GPBUInt64ObjectDictionary *dict =
+  const NSString* kObjects[] = { @"abc", @"def", @"ghi", @"jkl" };
+  GPBUInt64ObjectDictionary<NSString*> *dict =
       [[GPBUInt64ObjectDictionary alloc] initWithObjects:kObjects
                                           forKeys:kKeys
                                             count:GPBARRAYSIZE(kObjects)];
@@ -3624,8 +3624,8 @@
   XCTAssertEqualObjects([dict objectForKey:34ULL], @"def");
 
   const uint64_t kKeys2[] = { 32ULL, 33ULL };
-  const id kObjects2[] = { @"ghi", @"abc" };
-  GPBUInt64ObjectDictionary *dict2 =
+  const NSString* kObjects2[] = { @"ghi", @"abc" };
+  GPBUInt64ObjectDictionary<NSString*> *dict2 =
       [[GPBUInt64ObjectDictionary alloc] initWithObjects:kObjects2
                                                  forKeys:kKeys2
                                                    count:GPBARRAYSIZE(kObjects2)];
diff --git a/objectivec/Tests/GPBDictionaryTests.pddm b/objectivec/Tests/GPBDictionaryTests.pddm
index ada93c6..0951294 100644
--- a/objectivec/Tests/GPBDictionaryTests.pddm
+++ b/objectivec/Tests/GPBDictionaryTests.pddm
@@ -30,7 +30,7 @@
 
 //%PDDM-DEFINE TEST_FOR_POD_KEY(KEY_NAME, KEY_TYPE, KEY1, KEY2, KEY3, KEY4)
 //%TESTS_FOR_POD_VALUES(KEY_NAME, KEY_TYPE, , , KEY1, KEY2, KEY3, KEY4)
-//%TESTS_FOR_POD_KEY_OBJECT_VALUE(KEY_NAME, KEY_TYPE, KEY1, KEY2, KEY3, KEY4, Object, id, @"abc", @"def", @"ghi", @"jkl")
+//%TESTS_FOR_POD_KEY_OBJECT_VALUE(KEY_NAME, KEY_TYPE, KEY1, KEY2, KEY3, KEY4, Object, NSString*, @"abc", @"def", @"ghi", @"jkl")
 
 //%PDDM-DEFINE TESTS_FOR_POD_VALUES(KEY_NAME, KEY_TYPE, KisP, KSUFFIX, KEY1, KEY2, KEY3, KEY4)
 //%TEST_HELPERS(KEY_NAME, KEY_TYPE, KisP)
@@ -50,6 +50,13 @@
 //%PDDM-DEFINE TESTS_FOR_POD_KEY_OBJECT_VALUE(KEY_NAME, KEY_TYPE, KEY1, KEY2, KEY3, KEY4, VALUE_NAME, VALUE_TYPE, VAL1, VAL2, VAL3, VAL4)
 //%TESTS_COMMON(KEY_NAME, KEY_TYPE, , , KEY1, KEY2, KEY3, KEY4, VALUE_NAME, VALUE_TYPE, Objects, object, OBJECT, , VAL1, VAL2, VAL3, VAL4)
 
+//%PDDM-DEFINE DICTIONARY_CLASS_DECLPOD(KEY_NAME, VALUE_NAME, VALUE_TYPE)
+//%GPB##KEY_NAME##VALUE_NAME##Dictionary
+//%PDDM-DEFINE DICTIONARY_CLASS_DECLEnum(KEY_NAME, VALUE_NAME, VALUE_TYPE)
+//%GPB##KEY_NAME##VALUE_NAME##Dictionary
+//%PDDM-DEFINE DICTIONARY_CLASS_DECLOBJECT(KEY_NAME, VALUE_NAME, VALUE_TYPE)
+//%GPB##KEY_NAME##VALUE_NAME##Dictionary<VALUE_TYPE>
+
 //%PDDM-DEFINE TESTS_COMMON(KEY_NAME, KEY_TYPE, KisP, KSUFFIX, KEY1, KEY2, KEY3, KEY4, VALUE_NAME, VALUE_TYPE, VSUFFIX, VNAME, VHELPER, VACCESSOR, VAL1, VAL2, VAL3, VAL4)
 //%#pragma mark - KEY_NAME -> VALUE_NAME
 //%
@@ -59,7 +66,7 @@
 //%@implementation GPB##KEY_NAME##VALUE_NAME##DictionaryTests
 //%
 //%- (void)testEmpty {
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict = [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] init];
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict = [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] init];
 //%  XCTAssertNotNil(dict);
 //%  XCTAssertEqual(dict.count, 0U);
 //%VALUE_NOT_FOUND##VHELPER(dict, KEY1)
@@ -71,7 +78,7 @@
 //%}
 //%
 //%- (void)testOne {
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict = [GPB##KEY_NAME##VALUE_NAME##Dictionary dictionaryWith##VNAME$u##:VAL1 forKey:KEY1];
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict = [GPB##KEY_NAME##VALUE_NAME##Dictionary dictionaryWith##VNAME$u##:VAL1 forKey:KEY1];
 //%  XCTAssertNotNil(dict);
 //%  XCTAssertEqual(dict.count, 1U);
 //%DECLARE_VALUE_STORAGE##VHELPER(VALUE_TYPE, VNAME)TEST_VALUE##VHELPER(dict, VNAME, KEY1, VAL1)
@@ -86,7 +93,7 @@
 //%- (void)testBasics {
 //%  const KEY_TYPE KisP##kKeys[] = { KEY1, KEY2, KEY3 };
 //%  const VALUE_TYPE k##VNAME$u##s[] = { VAL1, VAL2, VAL3 };
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWith##VNAME$u##s:k##VNAME$u##s
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##  forKeys:kKeys
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##    count:GPBARRAYSIZE(k##VNAME$u##s)];
@@ -137,27 +144,27 @@
 //%  const VALUE_TYPE k##VNAME$u##s1[] = { VAL1, VAL2, VAL3 };
 //%  const VALUE_TYPE k##VNAME$u##s2[] = { VAL1, VAL4, VAL3 };
 //%  const VALUE_TYPE k##VNAME$u##s3[] = { VAL1, VAL2, VAL3, VAL4 };
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict1 =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict1 =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWith##VNAME$u##s:k##VNAME$u##s1
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##  forKeys:kKeys1
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##    count:GPBARRAYSIZE(k##VNAME$u##s1)];
 //%  XCTAssertNotNil(dict1);
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict1prime =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict1prime =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWith##VNAME$u##s:k##VNAME$u##s1
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##  forKeys:kKeys1
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##    count:GPBARRAYSIZE(k##VNAME$u##s1)];
 //%  XCTAssertNotNil(dict1prime);
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict2 =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict2 =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWith##VNAME$u##s:k##VNAME$u##s2
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##  forKeys:kKeys1
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##    count:GPBARRAYSIZE(k##VNAME$u##s2)];
 //%  XCTAssertNotNil(dict2);
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict3 =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict3 =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWith##VNAME$u##s:k##VNAME$u##s1
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##  forKeys:kKeys2
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##    count:GPBARRAYSIZE(k##VNAME$u##s1)];
 //%  XCTAssertNotNil(dict3);
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict4 =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict4 =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWith##VNAME$u##s:k##VNAME$u##s3
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##  forKeys:kKeys1
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##    count:GPBARRAYSIZE(k##VNAME$u##s3)];
@@ -188,13 +195,13 @@
 //%- (void)testCopy {
 //%  const KEY_TYPE KisP##kKeys[] = { KEY1, KEY2, KEY3, KEY4 };
 //%  const VALUE_TYPE k##VNAME$u##s[] = { VAL1, VAL2, VAL3, VAL4 };
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWith##VNAME$u##s:k##VNAME$u##s
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##  forKeys:kKeys
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##    count:GPBARRAYSIZE(k##VNAME$u##s)];
 //%  XCTAssertNotNil(dict);
 //%
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict2 = [dict copy];
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict2 = [dict copy];
 //%  XCTAssertNotNil(dict2);
 //%
 //%  // Should be new object but equal.
@@ -209,13 +216,13 @@
 //%- (void)testDictionaryFromDictionary {
 //%  const KEY_TYPE KisP##kKeys[] = { KEY1, KEY2, KEY3, KEY4 };
 //%  const VALUE_TYPE k##VNAME$u##s[] = { VAL1, VAL2, VAL3, VAL4 };
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWith##VNAME$u##s:k##VNAME$u##s
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##  forKeys:kKeys
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##    count:GPBARRAYSIZE(k##VNAME$u##s)];
 //%  XCTAssertNotNil(dict);
 //%
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict2 =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict2 =
 //%      [GPB##KEY_NAME##VALUE_NAME##Dictionary dictionaryWithDictionary:dict];
 //%  XCTAssertNotNil(dict2);
 //%
@@ -226,7 +233,7 @@
 //%}
 //%
 //%- (void)testAdds {
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict = [GPB##KEY_NAME##VALUE_NAME##Dictionary dictionary];
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict = [GPB##KEY_NAME##VALUE_NAME##Dictionary dictionary];
 //%  XCTAssertNotNil(dict);
 //%
 //%  XCTAssertEqual(dict.count, 0U);
@@ -235,7 +242,7 @@
 //%
 //%  const KEY_TYPE KisP##kKeys[] = { KEY2, KEY3, KEY4 };
 //%  const VALUE_TYPE k##VNAME$u##s[] = { VAL2, VAL3, VAL4 };
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict2 =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict2 =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWith##VNAME$u##s:k##VNAME$u##s
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##  forKeys:kKeys
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##    count:GPBARRAYSIZE(k##VNAME$u##s)];
@@ -253,7 +260,7 @@
 //%- (void)testRemove {
 //%  const KEY_TYPE KisP##kKeys[] = { KEY1, KEY2, KEY3, KEY4 };
 //%  const VALUE_TYPE k##VNAME$u##s[] = { VAL1, VAL2, VAL3, VAL4 };
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWith##VNAME$u##s:k##VNAME$u##s
 //%           KEY_NAME$S VALUE_NAME$S          ##VNAME$S##  forKeys:kKeys
 //%           KEY_NAME$S VALUE_NAME$S          ##VNAME$S##    count:GPBARRAYSIZE(k##VNAME$u##s)];
@@ -294,7 +301,7 @@
 //%- (void)testInplaceMutation {
 //%  const KEY_TYPE KisP##kKeys[] = { KEY1, KEY2, KEY3, KEY4 };
 //%  const VALUE_TYPE k##VNAME$u##s[] = { VAL1, VAL2, VAL3, VAL4 };
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWith##VNAME$u##s:k##VNAME$u##s
 //%           KEY_NAME$S VALUE_NAME$S          ##VNAME$S##  forKeys:kKeys
 //%           KEY_NAME$S VALUE_NAME$S          ##VNAME$S##    count:GPBARRAYSIZE(k##VNAME$u##s)];
@@ -321,7 +328,7 @@
 //%
 //%  const KEY_TYPE KisP##kKeys2[] = { KEY2, KEY3 };
 //%  const VALUE_TYPE k##VNAME$u##s2[] = { VAL3, VAL1 };
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict2 =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict2 =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWith##VNAME$u##s:k##VNAME$u##s2
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##  forKeys:kKeys2
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##    count:GPBARRAYSIZE(k##VNAME$u##s2)];
@@ -353,7 +360,7 @@
 //%- (void)testRawBasics {
 //%  const KEY_TYPE KisP##kKeys[] = { KEY1, KEY2, KEY3 };
 //%  const VALUE_TYPE kValues[] = { VAL1, VAL2, VAL3 };
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWithValidationFunction:TestingEnum_IsValidValue
 //%           KEY_NAME$S VALUE_NAME$S                                  rawValues:kValues
 //%           KEY_NAME$S VALUE_NAME$S                                    forKeys:kKeys
@@ -429,31 +436,31 @@
 //%  const VALUE_TYPE kValues1[] = { VAL1, VAL2, VAL3 };  // Unknown
 //%  const VALUE_TYPE kValues2[] = { VAL1, VAL4, VAL3 };  // Unknown
 //%  const VALUE_TYPE kValues3[] = { VAL1, VAL2, VAL3, VAL4 };  // Unknowns
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict1 =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict1 =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWithValidationFunction:TestingEnum_IsValidValue
 //%           KEY_NAME$S VALUE_NAME$S                                  rawValues:kValues1
 //%           KEY_NAME$S VALUE_NAME$S                                    forKeys:kKeys1
 //%           KEY_NAME$S VALUE_NAME$S                                      count:GPBARRAYSIZE(kValues1)];
 //%  XCTAssertNotNil(dict1);
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict1prime =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict1prime =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWithValidationFunction:TestingEnum_IsValidValue
 //%           KEY_NAME$S VALUE_NAME$S                                  rawValues:kValues1
 //%           KEY_NAME$S VALUE_NAME$S                                    forKeys:kKeys1
 //%           KEY_NAME$S VALUE_NAME$S                                      count:GPBARRAYSIZE(kValues1)];
 //%  XCTAssertNotNil(dict1prime);
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict2 =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict2 =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWithValidationFunction:TestingEnum_IsValidValue
 //%           KEY_NAME$S VALUE_NAME$S                                  rawValues:kValues2
 //%           KEY_NAME$S VALUE_NAME$S                                    forKeys:kKeys1
 //%           KEY_NAME$S VALUE_NAME$S                                      count:GPBARRAYSIZE(kValues2)];
 //%  XCTAssertNotNil(dict2);
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict3 =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict3 =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWithValidationFunction:TestingEnum_IsValidValue
 //%           KEY_NAME$S VALUE_NAME$S                                  rawValues:kValues1
 //%           KEY_NAME$S VALUE_NAME$S                                    forKeys:kKeys2
 //%           KEY_NAME$S VALUE_NAME$S                                      count:GPBARRAYSIZE(kValues1)];
 //%  XCTAssertNotNil(dict3);
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict4 =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict4 =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWithValidationFunction:TestingEnum_IsValidValue
 //%           KEY_NAME$S VALUE_NAME$S                                  rawValues:kValues3
 //%           KEY_NAME$S VALUE_NAME$S                                    forKeys:kKeys1
@@ -485,14 +492,14 @@
 //%- (void)testCopyWithUnknowns {
 //%  const KEY_TYPE KisP##kKeys[] = { KEY1, KEY2, KEY3, KEY4 };
 //%  const VALUE_TYPE kValues[] = { VAL1, VAL2, VAL3, VAL4 };  // Unknown
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWithValidationFunction:TestingEnum_IsValidValue
 //%           KEY_NAME$S VALUE_NAME$S                                  rawValues:kValues
 //%           KEY_NAME$S VALUE_NAME$S                                    forKeys:kKeys
 //%           KEY_NAME$S VALUE_NAME$S                                      count:GPBARRAYSIZE(kValues)];
 //%  XCTAssertNotNil(dict);
 //%
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict2 = [dict copy];
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict2 = [dict copy];
 //%  XCTAssertNotNil(dict2);
 //%
 //%  // Should be new pointer, but equal objects.
@@ -507,14 +514,14 @@
 //%- (void)testDictionaryFromDictionary {
 //%  const KEY_TYPE KisP##kKeys[] = { KEY1, KEY2, KEY3, KEY4 };
 //%  const VALUE_TYPE kValues[] = { VAL1, VAL2, VAL3, VAL4 };  // Unknowns
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWithValidationFunction:TestingEnum_IsValidValue
 //%           KEY_NAME$S VALUE_NAME$S                                  rawValues:kValues
 //%           KEY_NAME$S VALUE_NAME$S                                    forKeys:kKeys
 //%           KEY_NAME$S VALUE_NAME$S                                      count:GPBARRAYSIZE(kValues)];
 //%  XCTAssertNotNil(dict);
 //%
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict2 =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict2 =
 //%      [GPB##KEY_NAME##VALUE_NAME##Dictionary dictionaryWithDictionary:dict];
 //%  XCTAssertNotNil(dict2);
 //%
@@ -526,7 +533,7 @@
 //%}
 //%
 //%- (void)testUnknownAdds {
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict =
 //%    [GPB##KEY_NAME##VALUE_NAME##Dictionary dictionaryWithValidationFunction:TestingEnum_IsValidValue];
 //%  XCTAssertNotNil(dict);
 //%
@@ -539,7 +546,7 @@
 //%
 //%  const KEY_TYPE KisP##kKeys[] = { KEY1, KEY3, KEY4 };
 //%  const VALUE_TYPE kValues[] = { VAL1, VAL3, VAL4 };  // Unknown
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict2 =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict2 =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWithValues:kValues
 //%           KEY_NAME$S VALUE_NAME$S                        forKeys:kKeys
 //%           KEY_NAME$S VALUE_NAME$S                          count:GPBARRAYSIZE(kValues)];
@@ -559,7 +566,7 @@
 //%- (void)testUnknownRemove {
 //%  const KEY_TYPE KisP##kKeys[] = { KEY1, KEY2, KEY3, KEY4 };
 //%  const VALUE_TYPE kValues[] = { VAL1, VAL2, VAL3, VAL4 };  // Unknowns
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWithValidationFunction:TestingEnum_IsValidValue
 //%           KEY_NAME$S VALUE_NAME$S                                  rawValues:kValues
 //%           KEY_NAME$S VALUE_NAME$S                                    forKeys:kKeys
@@ -601,7 +608,7 @@
 //%- (void)testInplaceMutationUnknowns {
 //%  const KEY_TYPE KisP##kKeys[] = { KEY1, KEY2, KEY3, KEY4 };
 //%  const VALUE_TYPE kValues[] = { VAL1, VAL2, VAL3, VAL4 };  // Unknowns
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWithValidationFunction:TestingEnum_IsValidValue
 //%           KEY_NAME$S VALUE_NAME$S                                  rawValues:kValues
 //%           KEY_NAME$S VALUE_NAME$S                                    forKeys:kKeys
@@ -637,7 +644,7 @@
 //%
 //%  const KEY_TYPE KisP##kKeys2[] = { KEY2, KEY3 };
 //%  const VALUE_TYPE kValues2[] = { VAL3, VAL2 };  // Unknown
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict2 =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict2 =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWithValidationFunction:TestingEnum_IsValidValue
 //%           KEY_NAME$S VALUE_NAME$S                                  rawValues:kValues2
 //%           KEY_NAME$S VALUE_NAME$S                                    forKeys:kKeys2
@@ -657,14 +664,14 @@
 //%- (void)testCopyUnknowns {
 //%  const KEY_TYPE KisP##kKeys[] = { KEY1, KEY2, KEY3, KEY4 };
 //%  const VALUE_TYPE kValues[] = { VAL1, VAL2, VAL3, VAL4 };
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWithValidationFunction:TestingEnum_IsValidValue
 //%           KEY_NAME$S VALUE_NAME$S                                  rawValues:kValues
 //%           KEY_NAME$S VALUE_NAME$S                                    forKeys:kKeys
 //%           KEY_NAME$S VALUE_NAME$S                                      count:GPBARRAYSIZE(kValues)];
 //%  XCTAssertNotNil(dict);
 //%
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict2 = [dict copy];
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict2 = [dict copy];
 //%  XCTAssertNotNil(dict2);
 //%
 //%  // Should be new pointer, but equal objects.
@@ -782,7 +789,7 @@
 //%@implementation GPB##KEY_NAME##VALUE_NAME##DictionaryTests
 //%
 //%- (void)testEmpty {
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict = [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] init];
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict = [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] init];
 //%  XCTAssertNotNil(dict);
 //%  XCTAssertEqual(dict.count, 0U);
 //%VALUE_NOT_FOUND##VHELPER(dict, KEY1)
@@ -794,7 +801,7 @@
 //%}
 //%
 //%- (void)testOne {
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict = [GPB##KEY_NAME##VALUE_NAME##Dictionary dictionaryWith##VNAME$u##:VAL1 forKey:KEY1];
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict = [GPB##KEY_NAME##VALUE_NAME##Dictionary dictionaryWith##VNAME$u##:VAL1 forKey:KEY1];
 //%  XCTAssertNotNil(dict);
 //%  XCTAssertEqual(dict.count, 1U);
 //%DECLARE_VALUE_STORAGE##VHELPER(VALUE_TYPE, VNAME)TEST_VALUE##VHELPER(dict, VNAME, KEY1, VAL1)
@@ -809,7 +816,7 @@
 //%- (void)testBasics {
 //%  const KEY_TYPE KisP##kKeys[] = { KEY1, KEY2 };
 //%  const VALUE_TYPE k##VNAME$u##s[] = { VAL1, VAL2 };
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWith##VNAME$u##s:k##VNAME$u##s
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##  forKeys:kKeys
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##    count:GPBARRAYSIZE(k##VNAME$u##s)];
@@ -858,27 +865,27 @@
 //%  const VALUE_TYPE k##VNAME$u##s1[] = { VAL1, VAL2 };
 //%  const VALUE_TYPE k##VNAME$u##s2[] = { VAL2, VAL1 };
 //%  const VALUE_TYPE k##VNAME$u##s3[] = { VAL2 };
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict1 =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict1 =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWith##VNAME$u##s:k##VNAME$u##s1
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##  forKeys:kKeys1
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##    count:GPBARRAYSIZE(k##VNAME$u##s1)];
 //%  XCTAssertNotNil(dict1);
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict1prime =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict1prime =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWith##VNAME$u##s:k##VNAME$u##s1
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##  forKeys:kKeys1
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##    count:GPBARRAYSIZE(k##VNAME$u##s1)];
 //%  XCTAssertNotNil(dict1prime);
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict2 =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict2 =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWith##VNAME$u##s:k##VNAME$u##s2
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##  forKeys:kKeys1
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##    count:GPBARRAYSIZE(k##VNAME$u##s2)];
 //%  XCTAssertNotNil(dict2);
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict3 =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict3 =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWith##VNAME$u##s:k##VNAME$u##s1
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##  forKeys:kKeys2
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##    count:GPBARRAYSIZE(k##VNAME$u##s1)];
 //%  XCTAssertNotNil(dict3);
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict4 =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict4 =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWith##VNAME$u##s:k##VNAME$u##s3
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##  forKeys:kKeys1
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##    count:GPBARRAYSIZE(k##VNAME$u##s3)];
@@ -909,13 +916,13 @@
 //%- (void)testCopy {
 //%  const KEY_TYPE KisP##kKeys[] = { KEY1, KEY2 };
 //%  const VALUE_TYPE k##VNAME$u##s[] = { VAL1, VAL2 };
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWith##VNAME$u##s:k##VNAME$u##s
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##  forKeys:kKeys
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##    count:GPBARRAYSIZE(k##VNAME$u##s)];
 //%  XCTAssertNotNil(dict);
 //%
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict2 = [dict copy];
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict2 = [dict copy];
 //%  XCTAssertNotNil(dict2);
 //%
 //%  // Should be new object but equal.
@@ -930,13 +937,13 @@
 //%- (void)testDictionaryFromDictionary {
 //%  const KEY_TYPE KisP##kKeys[] = { KEY1, KEY2 };
 //%  const VALUE_TYPE k##VNAME$u##s[] = { VAL1, VAL2 };
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWith##VNAME$u##s:k##VNAME$u##s
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##  forKeys:kKeys
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##    count:GPBARRAYSIZE(k##VNAME$u##s)];
 //%  XCTAssertNotNil(dict);
 //%
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict2 =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict2 =
 //%      [GPB##KEY_NAME##VALUE_NAME##Dictionary dictionaryWithDictionary:dict];
 //%  XCTAssertNotNil(dict2);
 //%
@@ -947,7 +954,7 @@
 //%}
 //%
 //%- (void)testAdds {
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict = [GPB##KEY_NAME##VALUE_NAME##Dictionary dictionary];
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict = [GPB##KEY_NAME##VALUE_NAME##Dictionary dictionary];
 //%  XCTAssertNotNil(dict);
 //%
 //%  XCTAssertEqual(dict.count, 0U);
@@ -956,7 +963,7 @@
 //%
 //%  const KEY_TYPE KisP##kKeys[] = { KEY2 };
 //%  const VALUE_TYPE k##VNAME$u##s[] = { VAL2 };
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict2 =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict2 =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWith##VNAME$u##s:k##VNAME$u##s
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##  forKeys:kKeys
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##    count:GPBARRAYSIZE(k##VNAME$u##s)];
@@ -972,7 +979,7 @@
 //%- (void)testRemove {
 //%  const KEY_TYPE KisP##kKeys[] = { KEY1, KEY2};
 //%  const VALUE_TYPE k##VNAME$u##s[] = { VAL1, VAL2 };
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWith##VNAME$u##s:k##VNAME$u##s
 //%           KEY_NAME$S VALUE_NAME$S          ##VNAME$S##  forKeys:kKeys
 //%           KEY_NAME$S VALUE_NAME$S          ##VNAME$S##    count:GPBARRAYSIZE(k##VNAME$u##s)];
@@ -1000,7 +1007,7 @@
 //%- (void)testInplaceMutation {
 //%  const KEY_TYPE KisP##kKeys[] = { KEY1, KEY2 };
 //%  const VALUE_TYPE k##VNAME$u##s[] = { VAL1, VAL2 };
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWith##VNAME$u##s:k##VNAME$u##s
 //%           KEY_NAME$S VALUE_NAME$S          ##VNAME$S##  forKeys:kKeys
 //%           KEY_NAME$S VALUE_NAME$S          ##VNAME$S##    count:GPBARRAYSIZE(k##VNAME$u##s)];
@@ -1021,7 +1028,7 @@
 //%
 //%  const KEY_TYPE KisP##kKeys2[] = { KEY2, KEY1 };
 //%  const VALUE_TYPE k##VNAME$u##s2[] = { VAL2, VAL1 };
-//%  GPB##KEY_NAME##VALUE_NAME##Dictionary *dict2 =
+//%  DICTIONARY_CLASS_DECL##VHELPER(KEY_NAME, VALUE_NAME, VALUE_TYPE) *dict2 =
 //%      [[GPB##KEY_NAME##VALUE_NAME##Dictionary alloc] initWith##VNAME$u##s:k##VNAME$u##s2
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##  forKeys:kKeys2
 //%           KEY_NAME$S VALUE_NAME$S                 ##VNAME$S##    count:GPBARRAYSIZE(k##VNAME$u##s2)];
diff --git a/objectivec/google/protobuf/Api.pbobjc.h b/objectivec/google/protobuf/Api.pbobjc.h
index c3cf8e9..8d82b15 100644
--- a/objectivec/google/protobuf/Api.pbobjc.h
+++ b/objectivec/google/protobuf/Api.pbobjc.h
@@ -11,6 +11,9 @@
 
 CF_EXTERN_C_BEGIN
 
+@class GPBMethod;
+@class GPBMixin;
+@class GPBOption;
 @class GPBSourceContext;
 GPB_ENUM_FWD_DECLARE(GPBSyntax);
 
@@ -47,13 +50,11 @@
 @property(nonatomic, readwrite, copy, null_resettable) NSString *name;
 
 // The methods of this api, in unspecified order.
-// |methodsArray| contains |GPBMethod|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *methodsArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBMethod*> *methodsArray;
 @property(nonatomic, readonly) NSUInteger methodsArray_Count;
 
 // Any metadata attached to the API.
-// |optionsArray| contains |GPBOption|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *optionsArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBOption*> *optionsArray;
 @property(nonatomic, readonly) NSUInteger optionsArray_Count;
 
 // A version string for this api. If specified, must have the form
@@ -84,8 +85,7 @@
 @property(nonatomic, readwrite, strong, null_resettable) GPBSourceContext *sourceContext;
 
 // Included APIs. See [Mixin][].
-// |mixinsArray| contains |GPBMixin|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *mixinsArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBMixin*> *mixinsArray;
 @property(nonatomic, readonly) NSUInteger mixinsArray_Count;
 
 // The source syntax of the service.
@@ -127,8 +127,7 @@
 @property(nonatomic, readwrite) BOOL responseStreaming;
 
 // Any metadata attached to the method.
-// |optionsArray| contains |GPBOption|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *optionsArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBOption*> *optionsArray;
 @property(nonatomic, readonly) NSUInteger optionsArray_Count;
 
 // The source syntax of this method.
diff --git a/objectivec/google/protobuf/Descriptor.pbobjc.h b/objectivec/google/protobuf/Descriptor.pbobjc.h
index 9c43cfd..2ab2024 100644
--- a/objectivec/google/protobuf/Descriptor.pbobjc.h
+++ b/objectivec/google/protobuf/Descriptor.pbobjc.h
@@ -11,14 +11,28 @@
 
 CF_EXTERN_C_BEGIN
 
+@class GPBDescriptorProto;
+@class GPBDescriptorProto_ExtensionRange;
+@class GPBDescriptorProto_ReservedRange;
+@class GPBEnumDescriptorProto;
 @class GPBEnumOptions;
+@class GPBEnumValueDescriptorProto;
 @class GPBEnumValueOptions;
+@class GPBFieldDescriptorProto;
 @class GPBFieldOptions;
+@class GPBFileDescriptorProto;
 @class GPBFileOptions;
+@class GPBGeneratedCodeInfo_Annotation;
 @class GPBMessageOptions;
+@class GPBMethodDescriptorProto;
 @class GPBMethodOptions;
+@class GPBOneofDescriptorProto;
+@class GPBServiceDescriptorProto;
 @class GPBServiceOptions;
 @class GPBSourceCodeInfo;
+@class GPBSourceCodeInfo_Location;
+@class GPBUninterpretedOption;
+@class GPBUninterpretedOption_NamePart;
 
 NS_ASSUME_NONNULL_BEGIN
 
@@ -151,8 +165,7 @@
 // files it parses.
 @interface GPBFileDescriptorSet : GPBMessage
 
-// |fileArray| contains |GPBFileDescriptorProto|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *fileArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBFileDescriptorProto*> *fileArray;
 @property(nonatomic, readonly) NSUInteger fileArray_Count;
 
 @end
@@ -186,8 +199,7 @@
 @property(nonatomic, readwrite, copy, null_resettable) NSString *package;
 
 // Names of files imported by this file.
-// |dependencyArray| contains |NSString|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *dependencyArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<NSString*> *dependencyArray;
 @property(nonatomic, readonly) NSUInteger dependencyArray_Count;
 
 // Indexes of the public imported files in the dependency list above.
@@ -200,20 +212,16 @@
 @property(nonatomic, readonly) NSUInteger weakDependencyArray_Count;
 
 // All top-level definitions in this file.
-// |messageTypeArray| contains |GPBDescriptorProto|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *messageTypeArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBDescriptorProto*> *messageTypeArray;
 @property(nonatomic, readonly) NSUInteger messageTypeArray_Count;
 
-// |enumTypeArray| contains |GPBEnumDescriptorProto|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *enumTypeArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBEnumDescriptorProto*> *enumTypeArray;
 @property(nonatomic, readonly) NSUInteger enumTypeArray_Count;
 
-// |serviceArray| contains |GPBServiceDescriptorProto|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *serviceArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBServiceDescriptorProto*> *serviceArray;
 @property(nonatomic, readonly) NSUInteger serviceArray_Count;
 
-// |extensionArray| contains |GPBFieldDescriptorProto|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *extensionArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBFieldDescriptorProto*> *extensionArray;
 @property(nonatomic, readonly) NSUInteger extensionArray_Count;
 
 @property(nonatomic, readwrite) BOOL hasOptions;
@@ -254,41 +262,33 @@
 @property(nonatomic, readwrite) BOOL hasName;
 @property(nonatomic, readwrite, copy, null_resettable) NSString *name;
 
-// |fieldArray| contains |GPBFieldDescriptorProto|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *fieldArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBFieldDescriptorProto*> *fieldArray;
 @property(nonatomic, readonly) NSUInteger fieldArray_Count;
 
-// |extensionArray| contains |GPBFieldDescriptorProto|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *extensionArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBFieldDescriptorProto*> *extensionArray;
 @property(nonatomic, readonly) NSUInteger extensionArray_Count;
 
-// |nestedTypeArray| contains |GPBDescriptorProto|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *nestedTypeArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBDescriptorProto*> *nestedTypeArray;
 @property(nonatomic, readonly) NSUInteger nestedTypeArray_Count;
 
-// |enumTypeArray| contains |GPBEnumDescriptorProto|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *enumTypeArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBEnumDescriptorProto*> *enumTypeArray;
 @property(nonatomic, readonly) NSUInteger enumTypeArray_Count;
 
-// |extensionRangeArray| contains |GPBDescriptorProto_ExtensionRange|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *extensionRangeArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBDescriptorProto_ExtensionRange*> *extensionRangeArray;
 @property(nonatomic, readonly) NSUInteger extensionRangeArray_Count;
 
-// |oneofDeclArray| contains |GPBOneofDescriptorProto|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *oneofDeclArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBOneofDescriptorProto*> *oneofDeclArray;
 @property(nonatomic, readonly) NSUInteger oneofDeclArray_Count;
 
 @property(nonatomic, readwrite) BOOL hasOptions;
 @property(nonatomic, readwrite, strong, null_resettable) GPBMessageOptions *options;
 
-// |reservedRangeArray| contains |GPBDescriptorProto_ReservedRange|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *reservedRangeArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBDescriptorProto_ReservedRange*> *reservedRangeArray;
 @property(nonatomic, readonly) NSUInteger reservedRangeArray_Count;
 
 // Reserved field names, which may not be used by fields in the same message.
 // A given name may only be reserved once.
-// |reservedNameArray| contains |NSString|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *reservedNameArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<NSString*> *reservedNameArray;
 @property(nonatomic, readonly) NSUInteger reservedNameArray_Count;
 
 @end
@@ -430,8 +430,7 @@
 @property(nonatomic, readwrite) BOOL hasName;
 @property(nonatomic, readwrite, copy, null_resettable) NSString *name;
 
-// |valueArray| contains |GPBEnumValueDescriptorProto|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *valueArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBEnumValueDescriptorProto*> *valueArray;
 @property(nonatomic, readonly) NSUInteger valueArray_Count;
 
 @property(nonatomic, readwrite) BOOL hasOptions;
@@ -475,8 +474,7 @@
 @property(nonatomic, readwrite) BOOL hasName;
 @property(nonatomic, readwrite, copy, null_resettable) NSString *name;
 
-// |methodArray| contains |GPBMethodDescriptorProto|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *methodArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBMethodDescriptorProto*> *methodArray;
 @property(nonatomic, readonly) NSUInteger methodArray_Count;
 
 @property(nonatomic, readwrite) BOOL hasOptions;
@@ -650,8 +648,7 @@
 @property(nonatomic, readwrite) BOOL javananoUseDeprecatedPackage;
 
 // The parser stores options it doesn't recognize here. See above.
-// |uninterpretedOptionArray| contains |GPBUninterpretedOption|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *uninterpretedOptionArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBUninterpretedOption*> *uninterpretedOptionArray;
 @property(nonatomic, readonly) NSUInteger uninterpretedOptionArray_Count;
 
 @end
@@ -727,8 +724,7 @@
 @property(nonatomic, readwrite) BOOL mapEntry;
 
 // The parser stores options it doesn't recognize here. See above.
-// |uninterpretedOptionArray| contains |GPBUninterpretedOption|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *uninterpretedOptionArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBUninterpretedOption*> *uninterpretedOptionArray;
 @property(nonatomic, readonly) NSUInteger uninterpretedOptionArray_Count;
 
 @end
@@ -817,8 +813,7 @@
 @property(nonatomic, readwrite) BOOL weak;
 
 // The parser stores options it doesn't recognize here. See above.
-// |uninterpretedOptionArray| contains |GPBUninterpretedOption|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *uninterpretedOptionArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBUninterpretedOption*> *uninterpretedOptionArray;
 @property(nonatomic, readonly) NSUInteger uninterpretedOptionArray_Count;
 
 @end
@@ -846,8 +841,7 @@
 @property(nonatomic, readwrite) BOOL deprecated;
 
 // The parser stores options it doesn't recognize here. See above.
-// |uninterpretedOptionArray| contains |GPBUninterpretedOption|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *uninterpretedOptionArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBUninterpretedOption*> *uninterpretedOptionArray;
 @property(nonatomic, readonly) NSUInteger uninterpretedOptionArray_Count;
 
 @end
@@ -869,8 +863,7 @@
 @property(nonatomic, readwrite) BOOL deprecated;
 
 // The parser stores options it doesn't recognize here. See above.
-// |uninterpretedOptionArray| contains |GPBUninterpretedOption|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *uninterpretedOptionArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBUninterpretedOption*> *uninterpretedOptionArray;
 @property(nonatomic, readonly) NSUInteger uninterpretedOptionArray_Count;
 
 @end
@@ -892,8 +885,7 @@
 @property(nonatomic, readwrite) BOOL deprecated;
 
 // The parser stores options it doesn't recognize here. See above.
-// |uninterpretedOptionArray| contains |GPBUninterpretedOption|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *uninterpretedOptionArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBUninterpretedOption*> *uninterpretedOptionArray;
 @property(nonatomic, readonly) NSUInteger uninterpretedOptionArray_Count;
 
 @end
@@ -915,8 +907,7 @@
 @property(nonatomic, readwrite) BOOL deprecated;
 
 // The parser stores options it doesn't recognize here. See above.
-// |uninterpretedOptionArray| contains |GPBUninterpretedOption|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *uninterpretedOptionArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBUninterpretedOption*> *uninterpretedOptionArray;
 @property(nonatomic, readonly) NSUInteger uninterpretedOptionArray_Count;
 
 @end
@@ -941,8 +932,7 @@
 // in them.
 @interface GPBUninterpretedOption : GPBMessage
 
-// |nameArray| contains |GPBUninterpretedOption_NamePart|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *nameArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBUninterpretedOption_NamePart*> *nameArray;
 @property(nonatomic, readonly) NSUInteger nameArray_Count;
 
 // The value of the uninterpreted option, in whatever type the tokenizer
@@ -1042,8 +1032,7 @@
 // - Code which tries to interpret locations should probably be designed to
 //   ignore those that it doesn't understand, as more types of locations could
 //   be recorded in the future.
-// |locationArray| contains |GPBSourceCodeInfo_Location|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *locationArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBSourceCodeInfo_Location*> *locationArray;
 @property(nonatomic, readonly) NSUInteger locationArray_Count;
 
 @end
@@ -1147,8 +1136,7 @@
 @property(nonatomic, readwrite) BOOL hasTrailingComments;
 @property(nonatomic, readwrite, copy, null_resettable) NSString *trailingComments;
 
-// |leadingDetachedCommentsArray| contains |NSString|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *leadingDetachedCommentsArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<NSString*> *leadingDetachedCommentsArray;
 @property(nonatomic, readonly) NSUInteger leadingDetachedCommentsArray_Count;
 
 @end
@@ -1166,8 +1154,7 @@
 
 // An Annotation connects some span of text in generated code to an element
 // of its generating .proto file.
-// |annotationArray| contains |GPBGeneratedCodeInfo_Annotation|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *annotationArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBGeneratedCodeInfo_Annotation*> *annotationArray;
 @property(nonatomic, readonly) NSUInteger annotationArray_Count;
 
 @end
diff --git a/objectivec/google/protobuf/FieldMask.pbobjc.h b/objectivec/google/protobuf/FieldMask.pbobjc.h
index 4e4ec38..f4bc265 100644
--- a/objectivec/google/protobuf/FieldMask.pbobjc.h
+++ b/objectivec/google/protobuf/FieldMask.pbobjc.h
@@ -155,8 +155,7 @@
 @interface GPBFieldMask : GPBMessage
 
 // The set of field mask paths.
-// |pathsArray| contains |NSString|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *pathsArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<NSString*> *pathsArray;
 @property(nonatomic, readonly) NSUInteger pathsArray_Count;
 
 @end
diff --git a/objectivec/google/protobuf/Struct.pbobjc.h b/objectivec/google/protobuf/Struct.pbobjc.h
index f40414f..293dea4 100644
--- a/objectivec/google/protobuf/Struct.pbobjc.h
+++ b/objectivec/google/protobuf/Struct.pbobjc.h
@@ -13,6 +13,7 @@
 
 @class GPBListValue;
 @class GPBStruct;
+@class GPBValue;
 
 NS_ASSUME_NONNULL_BEGIN
 
@@ -60,8 +61,7 @@
 @interface GPBStruct : GPBMessage
 
 // Map of dynamically typed values.
-// |fields| values are |GPBValue|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableDictionary *fields;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableDictionary<NSString*, GPBValue*> *fields;
 @property(nonatomic, readonly) NSUInteger fields_Count;
 
 @end
@@ -135,8 +135,7 @@
 @interface GPBListValue : GPBMessage
 
 // Repeated field of dynamically typed values.
-// |valuesArray| contains |GPBValue|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *valuesArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBValue*> *valuesArray;
 @property(nonatomic, readonly) NSUInteger valuesArray_Count;
 
 @end
diff --git a/objectivec/google/protobuf/Type.pbobjc.h b/objectivec/google/protobuf/Type.pbobjc.h
index e4c7a25..a7d03a2 100644
--- a/objectivec/google/protobuf/Type.pbobjc.h
+++ b/objectivec/google/protobuf/Type.pbobjc.h
@@ -12,6 +12,9 @@
 CF_EXTERN_C_BEGIN
 
 @class GPBAny;
+@class GPBEnumValue;
+@class GPBField;
+@class GPBOption;
 @class GPBSourceContext;
 
 NS_ASSUME_NONNULL_BEGIN
@@ -150,18 +153,15 @@
 @property(nonatomic, readwrite, copy, null_resettable) NSString *name;
 
 // The list of fields.
-// |fieldsArray| contains |GPBField|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *fieldsArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBField*> *fieldsArray;
 @property(nonatomic, readonly) NSUInteger fieldsArray_Count;
 
 // The list of types appearing in `oneof` definitions in this type.
-// |oneofsArray| contains |NSString|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *oneofsArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<NSString*> *oneofsArray;
 @property(nonatomic, readonly) NSUInteger oneofsArray_Count;
 
 // The protocol buffer options.
-// |optionsArray| contains |GPBOption|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *optionsArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBOption*> *optionsArray;
 @property(nonatomic, readonly) NSUInteger optionsArray_Count;
 
 // The source context.
@@ -218,8 +218,7 @@
 @property(nonatomic, readwrite) BOOL packed;
 
 // The protocol buffer options.
-// |optionsArray| contains |GPBOption|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *optionsArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBOption*> *optionsArray;
 @property(nonatomic, readonly) NSUInteger optionsArray_Count;
 
 // The field JSON name.
@@ -253,13 +252,11 @@
 @property(nonatomic, readwrite, copy, null_resettable) NSString *name;
 
 // Enum value definitions.
-// |enumvalueArray| contains |GPBEnumValue|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *enumvalueArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBEnumValue*> *enumvalueArray;
 @property(nonatomic, readonly) NSUInteger enumvalueArray_Count;
 
 // Protocol buffer options.
-// |optionsArray| contains |GPBOption|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *optionsArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBOption*> *optionsArray;
 @property(nonatomic, readonly) NSUInteger optionsArray_Count;
 
 // The source context.
@@ -292,8 +289,7 @@
 @property(nonatomic, readwrite) int32_t number;
 
 // Protocol buffer options.
-// |optionsArray| contains |GPBOption|
-@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray *optionsArray;
+@property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBOption*> *optionsArray;
 @property(nonatomic, readonly) NSUInteger optionsArray_Count;
 
 @end
diff --git a/src/google/protobuf/compiler/main.cc b/src/google/protobuf/compiler/main.cc
index 97df536..66ad13b 100644
--- a/src/google/protobuf/compiler/main.cc
+++ b/src/google/protobuf/compiler/main.cc
@@ -78,7 +78,7 @@
 
   // Objective C
   google::protobuf::compiler::objectivec::ObjectiveCGenerator objc_generator;
-  cli.RegisterGenerator("--objc_out", &objc_generator,
+  cli.RegisterGenerator("--objc_out", "--objc_opt", &objc_generator,
                         "Generate Objective C header and source.");
 
   // JavaScript
diff --git a/src/google/protobuf/compiler/objectivec/objectivec_enum_field.cc b/src/google/protobuf/compiler/objectivec/objectivec_enum_field.cc
index 30a13dd..ecc77f6 100644
--- a/src/google/protobuf/compiler/objectivec/objectivec_enum_field.cc
+++ b/src/google/protobuf/compiler/objectivec/objectivec_enum_field.cc
@@ -44,6 +44,7 @@
 namespace objectivec {
 
 namespace {
+
 void SetEnumVariables(const FieldDescriptor* descriptor,
                       map<string, string>* variables) {
   string type = EnumName(descriptor->enum_type());
@@ -63,8 +64,9 @@
 }
 }  // namespace
 
-EnumFieldGenerator::EnumFieldGenerator(const FieldDescriptor* descriptor)
-    : SingleFieldGenerator(descriptor) {
+EnumFieldGenerator::EnumFieldGenerator(const FieldDescriptor* descriptor,
+                                       const Options& options)
+    : SingleFieldGenerator(descriptor, options) {
   SetEnumVariables(descriptor, &variables_);
 }
 
@@ -112,6 +114,7 @@
 
 void EnumFieldGenerator::DetermineForwardDeclarations(
     set<string>* fwd_decls) const {
+  SingleFieldGenerator::DetermineForwardDeclarations(fwd_decls);
   // If it is an enum defined in a different file, then we'll need a forward
   // declaration for it.  When it is in our file, all the enums are output
   // before the message, so it will be declared before it is needed.
@@ -123,14 +126,20 @@
 }
 
 RepeatedEnumFieldGenerator::RepeatedEnumFieldGenerator(
-    const FieldDescriptor* descriptor)
-    : RepeatedFieldGenerator(descriptor) {
+    const FieldDescriptor* descriptor, const Options& options)
+    : RepeatedFieldGenerator(descriptor, options) {
   SetEnumVariables(descriptor, &variables_);
   variables_["array_storage_type"] = "GPBEnumArray";
 }
 
 RepeatedEnumFieldGenerator::~RepeatedEnumFieldGenerator() {}
 
+void RepeatedEnumFieldGenerator::FinishInitialization(void) {
+  RepeatedFieldGenerator::FinishInitialization();
+  variables_["array_comment"] =
+      "// |" + variables_["name"] + "| contains |" + variables_["storage_type"] + "|\n";
+}
+
 void RepeatedEnumFieldGenerator::GenerateFieldDescriptionTypeSpecific(
     io::Printer* printer) const {
   printer->Print(
diff --git a/src/google/protobuf/compiler/objectivec/objectivec_enum_field.h b/src/google/protobuf/compiler/objectivec/objectivec_enum_field.h
index b629eae..ae2f57e 100644
--- a/src/google/protobuf/compiler/objectivec/objectivec_enum_field.h
+++ b/src/google/protobuf/compiler/objectivec/objectivec_enum_field.h
@@ -41,7 +41,8 @@
 namespace objectivec {
 
 class EnumFieldGenerator : public SingleFieldGenerator {
-  friend FieldGenerator* FieldGenerator::Make(const FieldDescriptor* field);
+  friend FieldGenerator* FieldGenerator::Make(const FieldDescriptor* field,
+                                              const Options& options);
 
  public:
   virtual void GenerateFieldDescriptionTypeSpecific(io::Printer* printer) const;
@@ -50,7 +51,7 @@
   virtual void DetermineForwardDeclarations(set<string>* fwd_decls) const;
 
  protected:
-  explicit EnumFieldGenerator(const FieldDescriptor* descriptor);
+  EnumFieldGenerator(const FieldDescriptor* descriptor, const Options& options);
   virtual ~EnumFieldGenerator();
 
  private:
@@ -58,13 +59,16 @@
 };
 
 class RepeatedEnumFieldGenerator : public RepeatedFieldGenerator {
-  friend FieldGenerator* FieldGenerator::Make(const FieldDescriptor* field);
+  friend FieldGenerator* FieldGenerator::Make(const FieldDescriptor* field,
+                                              const Options& options);
 
  public:
+  virtual void FinishInitialization();
   virtual void GenerateFieldDescriptionTypeSpecific(io::Printer* printer) const;
 
  protected:
-  RepeatedEnumFieldGenerator(const FieldDescriptor* descriptor);
+  RepeatedEnumFieldGenerator(const FieldDescriptor* descriptor,
+                             const Options& options);
   virtual ~RepeatedEnumFieldGenerator();
 
  private:
diff --git a/src/google/protobuf/compiler/objectivec/objectivec_field.cc b/src/google/protobuf/compiler/objectivec/objectivec_field.cc
index cf5d8cf..0934182 100644
--- a/src/google/protobuf/compiler/objectivec/objectivec_field.cc
+++ b/src/google/protobuf/compiler/objectivec/objectivec_field.cc
@@ -45,6 +45,7 @@
 namespace objectivec {
 
 namespace {
+
 void SetCommonFieldVariables(const FieldDescriptor* descriptor,
                              map<string, string>* variables) {
   string camel_case_name = FieldName(descriptor);
@@ -117,39 +118,40 @@
 
 }  // namespace
 
-FieldGenerator* FieldGenerator::Make(const FieldDescriptor* field) {
+FieldGenerator* FieldGenerator::Make(const FieldDescriptor* field,
+                                     const Options& options) {
   FieldGenerator* result = NULL;
   if (field->is_repeated()) {
     switch (GetObjectiveCType(field)) {
       case OBJECTIVECTYPE_MESSAGE: {
         if (field->is_map()) {
-          result = new MapFieldGenerator(field);
+          result = new MapFieldGenerator(field, options);
         } else {
-          result = new RepeatedMessageFieldGenerator(field);
+          result = new RepeatedMessageFieldGenerator(field, options);
         }
         break;
       }
       case OBJECTIVECTYPE_ENUM:
-        result = new RepeatedEnumFieldGenerator(field);
+        result = new RepeatedEnumFieldGenerator(field, options);
         break;
       default:
-        result = new RepeatedPrimitiveFieldGenerator(field);
+        result = new RepeatedPrimitiveFieldGenerator(field, options);
         break;
     }
   } else {
     switch (GetObjectiveCType(field)) {
       case OBJECTIVECTYPE_MESSAGE: {
-        result = new MessageFieldGenerator(field);
+        result = new MessageFieldGenerator(field, options);
         break;
       }
       case OBJECTIVECTYPE_ENUM:
-        result = new EnumFieldGenerator(field);
+        result = new EnumFieldGenerator(field, options);
         break;
       default:
         if (IsReferenceType(field)) {
-          result = new PrimitiveObjFieldGenerator(field);
+          result = new PrimitiveObjFieldGenerator(field, options);
         } else {
-          result = new PrimitiveFieldGenerator(field);
+          result = new PrimitiveFieldGenerator(field, options);
         }
         break;
     }
@@ -158,8 +160,8 @@
   return result;
 }
 
-
-FieldGenerator::FieldGenerator(const FieldDescriptor* descriptor)
+FieldGenerator::FieldGenerator(const FieldDescriptor* descriptor,
+                               const Options& options)
     : descriptor_(descriptor) {
   SetCommonFieldVariables(descriptor, &variables_);
 }
@@ -252,9 +254,9 @@
   }
 }
 
-SingleFieldGenerator::SingleFieldGenerator(
-    const FieldDescriptor* descriptor)
-    : FieldGenerator(descriptor) {
+SingleFieldGenerator::SingleFieldGenerator(const FieldDescriptor* descriptor,
+                                           const Options& options)
+    : FieldGenerator(descriptor, options) {
   // Nothing
 }
 
@@ -300,9 +302,9 @@
   return false;
 }
 
-ObjCObjFieldGenerator::ObjCObjFieldGenerator(
-    const FieldDescriptor* descriptor)
-    : SingleFieldGenerator(descriptor) {
+ObjCObjFieldGenerator::ObjCObjFieldGenerator(const FieldDescriptor* descriptor,
+                                             const Options& options)
+    : SingleFieldGenerator(descriptor, options) {
   variables_["property_storage_attribute"] = "strong";
   if (IsRetainedName(variables_["name"])) {
     variables_["storage_attribute"] = " NS_RETURNS_NOT_RETAINED";
@@ -342,18 +344,21 @@
 }
 
 RepeatedFieldGenerator::RepeatedFieldGenerator(
-    const FieldDescriptor* descriptor)
-    : ObjCObjFieldGenerator(descriptor) {
+    const FieldDescriptor* descriptor, const Options& options)
+    : ObjCObjFieldGenerator(descriptor, options) {
   // Repeated fields don't use the has index.
   variables_["has_index"] = "GPBNoHasBit";
+  // Default to no comment and let the cases needing it fill it in.
+  variables_["array_comment"] = "";
 }
 
 RepeatedFieldGenerator::~RepeatedFieldGenerator() {}
 
 void RepeatedFieldGenerator::FinishInitialization(void) {
   FieldGenerator::FinishInitialization();
-  variables_["array_comment"] =
-      "// |" + variables_["name"] + "| contains |" + variables_["storage_type"] + "|\n";
+  if (variables_.find("array_property_type") == variables_.end()) {
+    variables_["array_property_type"] = variable("array_storage_type");
+  }
 }
 
 void RepeatedFieldGenerator::GenerateFieldStorageDeclaration(
@@ -379,13 +384,13 @@
       variables_,
       "$comments$"
       "$array_comment$"
-      "@property(nonatomic, readwrite, strong, null_resettable) $array_storage_type$ *$name$$storage_attribute$;\n"
+      "@property(nonatomic, readwrite, strong, null_resettable) $array_property_type$ *$name$$storage_attribute$;\n"
       "@property(nonatomic, readonly) NSUInteger $name$_Count;\n");
   if (IsInitName(variables_.find("name")->second)) {
     // If property name starts with init we need to annotate it to get past ARC.
     // http://stackoverflow.com/questions/18723226/how-do-i-annotate-an-objective-c-property-with-an-objc-method-family/18723227#18723227
     printer->Print(variables_,
-                   "- ($array_storage_type$ *)$name$ GPB_METHOD_FAMILY_NONE;\n");
+                   "- ($array_property_type$ *)$name$ GPB_METHOD_FAMILY_NONE;\n");
   }
   printer->Print("\n");
 }
@@ -395,7 +400,8 @@
   return false;
 }
 
-FieldGeneratorMap::FieldGeneratorMap(const Descriptor* descriptor)
+FieldGeneratorMap::FieldGeneratorMap(const Descriptor* descriptor,
+                                     const Options& options)
     : descriptor_(descriptor),
       field_generators_(
           new scoped_ptr<FieldGenerator>[descriptor->field_count()]),
@@ -403,10 +409,12 @@
           new scoped_ptr<FieldGenerator>[descriptor->extension_count()]) {
   // Construct all the FieldGenerators.
   for (int i = 0; i < descriptor->field_count(); i++) {
-    field_generators_[i].reset(FieldGenerator::Make(descriptor->field(i)));
+    field_generators_[i].reset(
+        FieldGenerator::Make(descriptor->field(i), options));
   }
   for (int i = 0; i < descriptor->extension_count(); i++) {
-    extension_generators_[i].reset(FieldGenerator::Make(descriptor->extension(i)));
+    extension_generators_[i].reset(
+        FieldGenerator::Make(descriptor->extension(i), options));
   }
 }
 
diff --git a/src/google/protobuf/compiler/objectivec/objectivec_field.h b/src/google/protobuf/compiler/objectivec/objectivec_field.h
index 130a52d..e8a20a7 100644
--- a/src/google/protobuf/compiler/objectivec/objectivec_field.h
+++ b/src/google/protobuf/compiler/objectivec/objectivec_field.h
@@ -49,24 +49,31 @@
 
 class FieldGenerator {
  public:
-  static FieldGenerator* Make(const FieldDescriptor* field);
+  static FieldGenerator* Make(const FieldDescriptor* field,
+                              const Options& options);
 
   virtual ~FieldGenerator();
 
+  // Exposed for subclasses to fill in.
   virtual void GenerateFieldStorageDeclaration(io::Printer* printer) const = 0;
   virtual void GeneratePropertyDeclaration(io::Printer* printer) const = 0;
-
   virtual void GeneratePropertyImplementation(io::Printer* printer) const = 0;
 
-  virtual void GenerateFieldDescription(io::Printer* printer) const;
+  // Called by GenerateFieldDescription, exposed for classes that need custom
+  // generation.
   virtual void GenerateFieldDescriptionTypeSpecific(io::Printer* printer) const;
-  virtual void GenerateFieldNumberConstant(io::Printer* printer) const;
 
+  // Exposed for subclasses to extend, base does nothing.
   virtual void GenerateCFunctionDeclarations(io::Printer* printer) const;
   virtual void GenerateCFunctionImplementations(io::Printer* printer) const;
 
+  // Exposed for subclasses, should always call it on the parent class also.
   virtual void DetermineForwardDeclarations(set<string>* fwd_decls) const;
 
+  // Used during generation, not intended to be extended by subclasses.
+  void GenerateFieldDescription(io::Printer* printer) const;
+  void GenerateFieldNumberConstant(io::Printer* printer) const;
+
   void SetOneofIndexBase(int index_base);
 
   string variable(const char* key) const {
@@ -81,7 +88,7 @@
   string raw_field_name() const { return variable("raw_field_name"); }
 
  protected:
-  explicit FieldGenerator(const FieldDescriptor* descriptor);
+  FieldGenerator(const FieldDescriptor* descriptor, const Options& options);
 
   virtual void FinishInitialization(void);
   virtual bool WantsHasProperty(void) const = 0;
@@ -103,7 +110,8 @@
   virtual void GeneratePropertyImplementation(io::Printer* printer) const;
 
  protected:
-  explicit SingleFieldGenerator(const FieldDescriptor* descriptor);
+  SingleFieldGenerator(const FieldDescriptor* descriptor,
+                       const Options& options);
   virtual bool WantsHasProperty(void) const;
 
  private:
@@ -119,7 +127,8 @@
   virtual void GeneratePropertyDeclaration(io::Printer* printer) const;
 
  protected:
-  explicit ObjCObjFieldGenerator(const FieldDescriptor* descriptor);
+  ObjCObjFieldGenerator(const FieldDescriptor* descriptor,
+                        const Options& options);
 
  private:
   GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(ObjCObjFieldGenerator);
@@ -135,7 +144,8 @@
   virtual void GeneratePropertyImplementation(io::Printer* printer) const;
 
  protected:
-  explicit RepeatedFieldGenerator(const FieldDescriptor* descriptor);
+  RepeatedFieldGenerator(const FieldDescriptor* descriptor,
+                         const Options& options);
   virtual void FinishInitialization(void);
   virtual bool WantsHasProperty(void) const;
 
@@ -146,7 +156,7 @@
 // Convenience class which constructs FieldGenerators for a Descriptor.
 class FieldGeneratorMap {
  public:
-  explicit FieldGeneratorMap(const Descriptor* descriptor);
+  FieldGeneratorMap(const Descriptor* descriptor, const Options& options);
   ~FieldGeneratorMap();
 
   const FieldGenerator& get(const FieldDescriptor* field) const;
diff --git a/src/google/protobuf/compiler/objectivec/objectivec_file.cc b/src/google/protobuf/compiler/objectivec/objectivec_file.cc
index 228c66f..cdf9ebb 100644
--- a/src/google/protobuf/compiler/objectivec/objectivec_file.cc
+++ b/src/google/protobuf/compiler/objectivec/objectivec_file.cc
@@ -50,17 +50,18 @@
 namespace compiler {
 namespace objectivec {
 
-FileGenerator::FileGenerator(const FileDescriptor *file)
+FileGenerator::FileGenerator(const FileDescriptor *file, const Options& options)
     : file_(file),
       root_class_name_(FileClassName(file)),
-      is_public_dep_(false) {
+      is_public_dep_(false),
+      options_(options) {
   for (int i = 0; i < file_->enum_type_count(); i++) {
     EnumGenerator *generator = new EnumGenerator(file_->enum_type(i));
     enum_generators_.push_back(generator);
   }
   for (int i = 0; i < file_->message_type_count(); i++) {
     MessageGenerator *generator =
-        new MessageGenerator(root_class_name_, file_->message_type(i));
+        new MessageGenerator(root_class_name_, file_->message_type(i), options_);
     message_generators_.push_back(generator);
   }
   for (int i = 0; i < file_->extension_count(); i++) {
@@ -352,7 +353,8 @@
       public_import_names.insert(file_->public_dependency(i)->name());
     }
     for (int i = 0; i < file_->dependency_count(); i++) {
-      FileGenerator *generator = new FileGenerator(file_->dependency(i));
+      FileGenerator *generator =
+          new FileGenerator(file_->dependency(i), options_);
       const string& name = file_->dependency(i)->name();
       bool public_import = (public_import_names.count(name) != 0);
       generator->SetIsPublicDependency(public_import);
diff --git a/src/google/protobuf/compiler/objectivec/objectivec_file.h b/src/google/protobuf/compiler/objectivec/objectivec_file.h
index 1bb4f0e..4c0fcd3 100644
--- a/src/google/protobuf/compiler/objectivec/objectivec_file.h
+++ b/src/google/protobuf/compiler/objectivec/objectivec_file.h
@@ -55,7 +55,7 @@
 
 class FileGenerator {
  public:
-  explicit FileGenerator(const FileDescriptor* file);
+  FileGenerator(const FileDescriptor* file, const Options& options);
   ~FileGenerator();
 
   void GenerateSource(io::Printer* printer);
@@ -84,6 +84,8 @@
   vector<ExtensionGenerator*> extension_generators_;
   bool is_public_dep_;
 
+  const Options options_;
+
   const vector<FileGenerator*>& DependencyGenerators();
 
   GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(FileGenerator);
diff --git a/src/google/protobuf/compiler/objectivec/objectivec_generator.cc b/src/google/protobuf/compiler/objectivec/objectivec_generator.cc
index 375b4e0..72e295d 100644
--- a/src/google/protobuf/compiler/objectivec/objectivec_generator.cc
+++ b/src/google/protobuf/compiler/objectivec/objectivec_generator.cc
@@ -49,21 +49,31 @@
                                    const string& parameter,
                                    OutputDirectory* output_directory,
                                    string* error) const {
-  // ObjC doesn't have any options at the moment, error if passed one.
+  // -----------------------------------------------------------------
+  // Parse generator options.
+
+  Options generation_options;
+
   vector<pair<string, string> > options;
   ParseGeneratorParameter(parameter, &options);
   for (int i = 0; i < options.size(); i++) {
-    *error = "error:: Unknown generator option: " + options[i].first;
-    return false;
+    if (options[i].first == "expected_prefixes_path") {
+      generation_options.expected_prefixes_path = options[i].second;
+    } else {
+      *error = "error: Unknown generator option: " + options[i].first;
+      return false;
+    }
   }
 
+  // -----------------------------------------------------------------
+
   // Validate the objc prefix/package pairing.
-  if (!ValidateObjCClassPrefix(file, error)) {
+  if (!ValidateObjCClassPrefix(file, generation_options, error)) {
     // *error will have been filled in.
     return false;
   }
 
-  FileGenerator file_generator(file);
+  FileGenerator file_generator(file, generation_options);
   string filepath = FilePath(file);
 
   // Generate header.
diff --git a/src/google/protobuf/compiler/objectivec/objectivec_helpers.cc b/src/google/protobuf/compiler/objectivec/objectivec_helpers.cc
index 8527b74..77a378c 100644
--- a/src/google/protobuf/compiler/objectivec/objectivec_helpers.cc
+++ b/src/google/protobuf/compiler/objectivec/objectivec_helpers.cc
@@ -58,6 +58,14 @@
 namespace compiler {
 namespace objectivec {
 
+Options::Options() {
+  // Default is the value of the env for the package prefixes.
+  const char* file_path = getenv("GPB_OBJC_EXPECTED_PACKAGE_PREFIXES");
+  if (file_path) {
+    expected_prefixes_path = file_path;
+  }
+}
+
 namespace {
 
 hash_set<string> MakeWordsMap(const char* const words[], size_t num_words) {
@@ -890,26 +898,26 @@
   return true;
 }
 
-bool LoadExpectedPackagePrefixes(map<string, string>* prefix_map,
-                                 string* out_expect_file_path,
+bool LoadExpectedPackagePrefixes(const Options &generation_options,
+                                 map<string, string>* prefix_map,
                                  string* out_error) {
-  const char* file_path = getenv("GPB_OBJC_EXPECTED_PACKAGE_PREFIXES");
-  if (file_path == NULL) {
+  if (generation_options.expected_prefixes_path.empty()) {
     return true;
   }
 
   int fd;
   do {
-    fd = open(file_path, O_RDONLY);
+    fd = open(generation_options.expected_prefixes_path.c_str(), O_RDONLY);
   } while (fd < 0 && errno == EINTR);
   if (fd < 0) {
     *out_error =
-        string(file_path) + ":0:0: error: Unable to open." + strerror(errno);
+        string("error: Unable to open \"") +
+        generation_options.expected_prefixes_path +
+        "\", " + strerror(errno);
     return false;
   }
   io::FileInputStream file_stream(fd);
   file_stream.SetCloseOnDelete(true);
-  *out_expect_file_path = file_path;
 
   Parser parser(prefix_map);
   const void* buf;
@@ -920,8 +928,9 @@
     }
 
     if (!parser.ParseChunk(StringPiece(static_cast<const char*>(buf), buf_len))) {
-      *out_error = string(file_path) + ":" + SimpleItoa(parser.last_line()) +
-                   ":0: error: " + parser.error_str();
+      *out_error =
+          string("error: ") + generation_options.expected_prefixes_path +
+          " Line " + SimpleItoa(parser.last_line()) + ", " + parser.error_str();
       return false;
     }
   }
@@ -930,7 +939,9 @@
 
 }  // namespace
 
-bool ValidateObjCClassPrefix(const FileDescriptor* file, string* out_error) {
+bool ValidateObjCClassPrefix(const FileDescriptor* file,
+                             const Options& generation_options,
+                             string* out_error) {
   const string prefix = file->options().objc_class_prefix();
   const string package = file->package();
 
@@ -939,11 +950,10 @@
 
   // Load any expected package prefixes to validate against those.
   map<string, string> expected_package_prefixes;
-  string expect_file_path;
-  if (!LoadExpectedPackagePrefixes(&expected_package_prefixes,
-                                   &expect_file_path, out_error)) {
-    // Any error, clear the entries that were read.
-    expected_package_prefixes.clear();
+  if (!LoadExpectedPackagePrefixes(generation_options,
+                                   &expected_package_prefixes,
+                                   out_error)) {
+    return false;
   }
 
   // Check: Error - See if there was an expected prefix for the package and
@@ -957,7 +967,7 @@
       return true;
     } else {
       // ...it didn't match!
-      *out_error = "protoc:0: error: Expected 'option objc_class_prefix = \"" +
+      *out_error = "error: Expected 'option objc_class_prefix = \"" +
                    package_match->second + "\";' in '" + file->name() + "'";
       if (prefix.length()) {
         *out_error += "; but found '" + prefix + "' instead";
@@ -980,11 +990,11 @@
        i != expected_package_prefixes.end(); ++i) {
     if (i->second == prefix) {
       *out_error =
-          "protoc:0: error: Found 'option objc_class_prefix = \"" + prefix +
+          "error: Found 'option objc_class_prefix = \"" + prefix +
           "\";' in '" + file->name() +
           "'; that prefix is already used for 'package " + i->first +
           ";'. It can only be reused by listing it in the expected file (" +
-          expect_file_path + ").";
+          generation_options.expected_prefixes_path + ").";
       return false;  // Only report first usage of the prefix.
     }
   }
@@ -1017,7 +1027,7 @@
          << "protoc:0: warning: Found unexpected 'option objc_class_prefix = \""
          << prefix << "\";' in '" << file->name() << "';"
          << " consider adding it to the expected prefixes file ("
-         << expect_file_path << ")." << endl;
+         << generation_options.expected_prefixes_path << ")." << endl;
     cerr.flush();
   }
 
diff --git a/src/google/protobuf/compiler/objectivec/objectivec_helpers.h b/src/google/protobuf/compiler/objectivec/objectivec_helpers.h
index 8574486..5b2dd19 100644
--- a/src/google/protobuf/compiler/objectivec/objectivec_helpers.h
+++ b/src/google/protobuf/compiler/objectivec/objectivec_helpers.h
@@ -42,6 +42,12 @@
 namespace compiler {
 namespace objectivec {
 
+// Generator options (see objectivec_generator.cc for a description of each):
+struct Options {
+  Options();
+  string expected_prefixes_path;
+};
+
 // Strips ".proto" or ".protodevel" from the end of a filename.
 string StripProto(const string& filename);
 
@@ -145,7 +151,9 @@
 // Checks the prefix for a given file and outputs any warnings needed, if
 // there are flat out errors, then out_error is filled in and the result is
 // false.
-bool ValidateObjCClassPrefix(const FileDescriptor* file, string *out_error);
+bool ValidateObjCClassPrefix(const FileDescriptor* file,
+                             const Options& generation_options,
+                             string* out_error);
 
 // Generate decode data needed for ObjC's GPBDecodeTextFormatName() to transform
 // the input into the expected output.
diff --git a/src/google/protobuf/compiler/objectivec/objectivec_map_field.cc b/src/google/protobuf/compiler/objectivec/objectivec_map_field.cc
index 2987f3d..2751e93 100644
--- a/src/google/protobuf/compiler/objectivec/objectivec_map_field.cc
+++ b/src/google/protobuf/compiler/objectivec/objectivec_map_field.cc
@@ -84,13 +84,14 @@
 
 }  // namespace
 
-MapFieldGenerator::MapFieldGenerator(const FieldDescriptor* descriptor)
-    : RepeatedFieldGenerator(descriptor) {
+MapFieldGenerator::MapFieldGenerator(const FieldDescriptor* descriptor,
+                                     const Options& options)
+    : RepeatedFieldGenerator(descriptor, options) {
   const FieldDescriptor* key_descriptor =
       descriptor->message_type()->FindFieldByName("key");
   const FieldDescriptor* value_descriptor =
       descriptor->message_type()->FindFieldByName("value");
-  value_field_generator_.reset(FieldGenerator::Make(value_descriptor));
+  value_field_generator_.reset(FieldGenerator::Make(value_descriptor, options));
 
   // Pull over some variables_ from the value.
   variables_["field_type"] = value_field_generator_->variable("field_type");
@@ -117,16 +118,27 @@
   variables_["fieldflags"] = BuildFlagsString(field_flags);
 
   ObjectiveCType value_objc_type = GetObjectiveCType(value_descriptor);
-  if ((GetObjectiveCType(key_descriptor) == OBJECTIVECTYPE_STRING) &&
+  const bool value_is_object_type =
       ((value_objc_type == OBJECTIVECTYPE_STRING) ||
        (value_objc_type == OBJECTIVECTYPE_DATA) ||
-       (value_objc_type == OBJECTIVECTYPE_MESSAGE))) {
+       (value_objc_type == OBJECTIVECTYPE_MESSAGE));
+  if ((GetObjectiveCType(key_descriptor) == OBJECTIVECTYPE_STRING) &&
+      value_is_object_type) {
     variables_["array_storage_type"] = "NSMutableDictionary";
+    variables_["array_property_type"] =
+        "NSMutableDictionary<NSString*, " +
+        value_field_generator_->variable("storage_type") + "*>";
   } else {
-    string base_name = MapEntryTypeName(key_descriptor, true);
-    base_name += MapEntryTypeName(value_descriptor, false);
-    base_name += "Dictionary";
-    variables_["array_storage_type"] = "GPB" + base_name;
+    string class_name("GPB");
+    class_name += MapEntryTypeName(key_descriptor, true);
+    class_name += MapEntryTypeName(value_descriptor, false);
+    class_name += "Dictionary";
+    variables_["array_storage_type"] = class_name;
+    if (value_is_object_type) {
+      variables_["array_property_type"] =
+          class_name + "<" +
+          value_field_generator_->variable("storage_type") + "*>";
+    }
   }
 }
 
@@ -138,15 +150,9 @@
   // values in the map are.
   const FieldDescriptor* value_descriptor =
       descriptor_->message_type()->FindFieldByName("value");
-  ObjectiveCType value_objc_type = GetObjectiveCType(value_descriptor);
-  if ((value_objc_type == OBJECTIVECTYPE_MESSAGE) ||
-      (value_objc_type == OBJECTIVECTYPE_DATA) ||
-      (value_objc_type == OBJECTIVECTYPE_STRING) ||
-      (value_objc_type == OBJECTIVECTYPE_ENUM)) {
+  if (GetObjectiveCType(value_descriptor) == OBJECTIVECTYPE_ENUM) {
     variables_["array_comment"] =
         "// |" + variables_["name"] + "| values are |" + value_field_generator_->variable("storage_type") + "|\n";
-  } else {
-    variables_["array_comment"] = "";
   }
 }
 
@@ -157,6 +163,19 @@
   value_field_generator_->GenerateFieldDescriptionTypeSpecific(printer);
 }
 
+void MapFieldGenerator::DetermineForwardDeclarations(
+    set<string>* fwd_decls) const {
+  RepeatedFieldGenerator::DetermineForwardDeclarations(fwd_decls);
+  const FieldDescriptor* value_descriptor =
+      descriptor_->message_type()->FindFieldByName("value");
+  if (GetObjectiveCType(value_descriptor) == OBJECTIVECTYPE_MESSAGE) {
+    const string& value_storage_type =
+        value_field_generator_->variable("storage_type");
+    fwd_decls->insert("@class " + value_storage_type);
+  }
+}
+
+
 }  // namespace objectivec
 }  // namespace compiler
 }  // namespace protobuf
diff --git a/src/google/protobuf/compiler/objectivec/objectivec_map_field.h b/src/google/protobuf/compiler/objectivec/objectivec_map_field.h
index 173541f..7351ea0 100644
--- a/src/google/protobuf/compiler/objectivec/objectivec_map_field.h
+++ b/src/google/protobuf/compiler/objectivec/objectivec_map_field.h
@@ -41,18 +41,22 @@
 namespace objectivec {
 
 class MapFieldGenerator : public RepeatedFieldGenerator {
-  friend FieldGenerator* FieldGenerator::Make(const FieldDescriptor* field);
+  friend FieldGenerator* FieldGenerator::Make(const FieldDescriptor* field,
+                                              const Options& options);
 
  public:
   virtual void FinishInitialization(void);
   virtual void GenerateFieldDescriptionTypeSpecific(io::Printer* printer) const;
 
  protected:
-  explicit MapFieldGenerator(const FieldDescriptor* descriptor);
+  MapFieldGenerator(const FieldDescriptor* descriptor, const Options& options);
   virtual ~MapFieldGenerator();
 
+  virtual void DetermineForwardDeclarations(set<string>* fwd_decls) const;
+
  private:
   scoped_ptr<FieldGenerator> value_field_generator_;
+
   GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(MapFieldGenerator);
 };
 
diff --git a/src/google/protobuf/compiler/objectivec/objectivec_message.cc b/src/google/protobuf/compiler/objectivec/objectivec_message.cc
index 32671d4..e0ea8bd 100644
--- a/src/google/protobuf/compiler/objectivec/objectivec_message.cc
+++ b/src/google/protobuf/compiler/objectivec/objectivec_message.cc
@@ -174,10 +174,11 @@
 }  // namespace
 
 MessageGenerator::MessageGenerator(const string& root_classname,
-                                   const Descriptor* descriptor)
+                                   const Descriptor* descriptor,
+                                   const Options& options)
     : root_classname_(root_classname),
       descriptor_(descriptor),
-      field_generators_(descriptor),
+      field_generators_(descriptor, options),
       class_name_(ClassName(descriptor_)) {
   for (int i = 0; i < descriptor_->extension_count(); i++) {
     extension_generators_.push_back(
@@ -196,7 +197,9 @@
 
   for (int i = 0; i < descriptor_->nested_type_count(); i++) {
     MessageGenerator* generator =
-        new MessageGenerator(root_classname_, descriptor_->nested_type(i));
+        new MessageGenerator(root_classname_,
+                             descriptor_->nested_type(i),
+                             options);
     nested_message_generators_.push_back(generator);
   }
 }
@@ -230,11 +233,6 @@
   if (!IsMapEntryMessage(descriptor_)) {
     for (int i = 0; i < descriptor_->field_count(); i++) {
       const FieldDescriptor* fieldDescriptor = descriptor_->field(i);
-      // If it is a the field is repeated, the type will be and *Array, and we
-      // don't need any forward decl.
-      if (fieldDescriptor->is_repeated()) {
-        continue;
-      }
       field_generators_.get(fieldDescriptor)
           .DetermineForwardDeclarations(fwd_decls);
     }
diff --git a/src/google/protobuf/compiler/objectivec/objectivec_message.h b/src/google/protobuf/compiler/objectivec/objectivec_message.h
index 06b536f..8565e76 100644
--- a/src/google/protobuf/compiler/objectivec/objectivec_message.h
+++ b/src/google/protobuf/compiler/objectivec/objectivec_message.h
@@ -54,7 +54,9 @@
 
 class MessageGenerator {
  public:
-  MessageGenerator(const string& root_classname, const Descriptor* descriptor);
+  MessageGenerator(const string& root_classname,
+                   const Descriptor* descriptor,
+                   const Options& options);
   ~MessageGenerator();
 
   void GenerateStaticVariablesInitialization(io::Printer* printer);
diff --git a/src/google/protobuf/compiler/objectivec/objectivec_message_field.cc b/src/google/protobuf/compiler/objectivec/objectivec_message_field.cc
index f2ce4e5..d6ccd6d 100644
--- a/src/google/protobuf/compiler/objectivec/objectivec_message_field.cc
+++ b/src/google/protobuf/compiler/objectivec/objectivec_message_field.cc
@@ -58,8 +58,9 @@
 
 }  // namespace
 
-MessageFieldGenerator::MessageFieldGenerator(const FieldDescriptor* descriptor)
-    : ObjCObjFieldGenerator(descriptor) {
+MessageFieldGenerator::MessageFieldGenerator(const FieldDescriptor* descriptor,
+                                             const Options& options)
+    : ObjCObjFieldGenerator(descriptor, options) {
   SetMessageVariables(descriptor, &variables_);
 }
 
@@ -67,6 +68,7 @@
 
 void MessageFieldGenerator::DetermineForwardDeclarations(
     set<string>* fwd_decls) const {
+  ObjCObjFieldGenerator::DetermineForwardDeclarations(fwd_decls);
   // Class name is already in "storage_type".
   fwd_decls->insert("@class " + variable("storage_type"));
 }
@@ -82,14 +84,24 @@
 }
 
 RepeatedMessageFieldGenerator::RepeatedMessageFieldGenerator(
-    const FieldDescriptor* descriptor)
-    : RepeatedFieldGenerator(descriptor) {
+    const FieldDescriptor* descriptor, const Options& options)
+    : RepeatedFieldGenerator(descriptor, options) {
   SetMessageVariables(descriptor, &variables_);
   variables_["array_storage_type"] = "NSMutableArray";
+  variables_["array_property_type"] =
+      "NSMutableArray<" + variables_["storage_type"] + "*>";
 }
 
 RepeatedMessageFieldGenerator::~RepeatedMessageFieldGenerator() {}
 
+void RepeatedMessageFieldGenerator::DetermineForwardDeclarations(
+    set<string>* fwd_decls) const {
+  RepeatedFieldGenerator::DetermineForwardDeclarations(fwd_decls);
+  // Class name is already in "storage_type".
+  fwd_decls->insert("@class " + variable("storage_type"));
+}
+
+
 }  // namespace objectivec
 }  // namespace compiler
 }  // namespace protobuf
diff --git a/src/google/protobuf/compiler/objectivec/objectivec_message_field.h b/src/google/protobuf/compiler/objectivec/objectivec_message_field.h
index 708ea56..d2dba15 100644
--- a/src/google/protobuf/compiler/objectivec/objectivec_message_field.h
+++ b/src/google/protobuf/compiler/objectivec/objectivec_message_field.h
@@ -41,10 +41,12 @@
 namespace objectivec {
 
 class MessageFieldGenerator : public ObjCObjFieldGenerator {
-  friend FieldGenerator* FieldGenerator::Make(const FieldDescriptor* field);
+  friend FieldGenerator* FieldGenerator::Make(const FieldDescriptor* field,
+                                              const Options& options);
 
  protected:
-  explicit MessageFieldGenerator(const FieldDescriptor* descriptor);
+  MessageFieldGenerator(const FieldDescriptor* descriptor,
+                        const Options& options);
   virtual ~MessageFieldGenerator();
   virtual bool WantsHasProperty(void) const;
 
@@ -56,12 +58,17 @@
 };
 
 class RepeatedMessageFieldGenerator : public RepeatedFieldGenerator {
-  friend FieldGenerator* FieldGenerator::Make(const FieldDescriptor* field);
+  friend FieldGenerator* FieldGenerator::Make(const FieldDescriptor* field,
+                                              const Options& options);
 
  protected:
-  explicit RepeatedMessageFieldGenerator(const FieldDescriptor* descriptor);
+  RepeatedMessageFieldGenerator(const FieldDescriptor* descriptor,
+                                const Options& options);
   virtual ~RepeatedMessageFieldGenerator();
 
+ public:
+  virtual void DetermineForwardDeclarations(set<string>* fwd_decls) const;
+
  private:
   GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(RepeatedMessageFieldGenerator);
 };
diff --git a/src/google/protobuf/compiler/objectivec/objectivec_primitive_field.cc b/src/google/protobuf/compiler/objectivec/objectivec_primitive_field.cc
index c185b66..ea7f1b9 100644
--- a/src/google/protobuf/compiler/objectivec/objectivec_primitive_field.cc
+++ b/src/google/protobuf/compiler/objectivec/objectivec_primitive_field.cc
@@ -74,7 +74,7 @@
     case OBJECTIVECTYPE_ENUM:
       return "int32_t";
     case OBJECTIVECTYPE_MESSAGE:
-      return NULL;
+      return NULL;  // Messages go through objectivec_message_field.cc|h.
   }
 
   // Some compilers report reaching end of function even though all cases of
@@ -107,7 +107,8 @@
     case OBJECTIVECTYPE_ENUM:
       return "Enum";
     case OBJECTIVECTYPE_MESSAGE:
-      return "";  // Want NSArray
+      // Want NSArray (but goes through objectivec_message_field.cc|h).
+      return "";
   }
 
   // Some compilers report reaching end of function even though all cases of
@@ -126,16 +127,16 @@
 }  // namespace
 
 PrimitiveFieldGenerator::PrimitiveFieldGenerator(
-    const FieldDescriptor* descriptor)
-    : SingleFieldGenerator(descriptor) {
+    const FieldDescriptor* descriptor, const Options& options)
+    : SingleFieldGenerator(descriptor, options) {
   SetPrimitiveVariables(descriptor, &variables_);
 }
 
 PrimitiveFieldGenerator::~PrimitiveFieldGenerator() {}
 
 PrimitiveObjFieldGenerator::PrimitiveObjFieldGenerator(
-    const FieldDescriptor* descriptor)
-    : ObjCObjFieldGenerator(descriptor) {
+    const FieldDescriptor* descriptor, const Options& options)
+    : ObjCObjFieldGenerator(descriptor, options) {
   SetPrimitiveVariables(descriptor, &variables_);
   variables_["property_storage_attribute"] = "copy";
 }
@@ -143,8 +144,8 @@
 PrimitiveObjFieldGenerator::~PrimitiveObjFieldGenerator() {}
 
 RepeatedPrimitiveFieldGenerator::RepeatedPrimitiveFieldGenerator(
-    const FieldDescriptor* descriptor)
-    : RepeatedFieldGenerator(descriptor) {
+    const FieldDescriptor* descriptor, const Options& options)
+    : RepeatedFieldGenerator(descriptor, options) {
   SetPrimitiveVariables(descriptor, &variables_);
 
   string base_name = PrimitiveArrayTypeName(descriptor);
@@ -152,19 +153,13 @@
     variables_["array_storage_type"] = "GPB" + base_name + "Array";
   } else {
     variables_["array_storage_type"] = "NSMutableArray";
+    variables_["array_property_type"] =
+        "NSMutableArray<" + variables_["storage_type"] + "*>";
   }
 }
 
 RepeatedPrimitiveFieldGenerator::~RepeatedPrimitiveFieldGenerator() {}
 
-void RepeatedPrimitiveFieldGenerator::FinishInitialization(void) {
-  RepeatedFieldGenerator::FinishInitialization();
-  if (IsPrimitiveType(descriptor_)) {
-    // No comment needed for primitive types.
-    variables_["array_comment"] = "";
-  }
-}
-
 }  // namespace objectivec
 }  // namespace compiler
 }  // namespace protobuf
diff --git a/src/google/protobuf/compiler/objectivec/objectivec_primitive_field.h b/src/google/protobuf/compiler/objectivec/objectivec_primitive_field.h
index 9bb7934..87139af 100644
--- a/src/google/protobuf/compiler/objectivec/objectivec_primitive_field.h
+++ b/src/google/protobuf/compiler/objectivec/objectivec_primitive_field.h
@@ -41,10 +41,12 @@
 namespace objectivec {
 
 class PrimitiveFieldGenerator : public SingleFieldGenerator {
-  friend FieldGenerator* FieldGenerator::Make(const FieldDescriptor* field);
+  friend FieldGenerator* FieldGenerator::Make(const FieldDescriptor* field,
+                                              const Options& options);
 
  protected:
-  explicit PrimitiveFieldGenerator(const FieldDescriptor* descriptor);
+  PrimitiveFieldGenerator(const FieldDescriptor* descriptor,
+                          const Options& options);
   virtual ~PrimitiveFieldGenerator();
 
  private:
@@ -52,10 +54,12 @@
 };
 
 class PrimitiveObjFieldGenerator : public ObjCObjFieldGenerator {
-  friend FieldGenerator* FieldGenerator::Make(const FieldDescriptor* field);
+  friend FieldGenerator* FieldGenerator::Make(const FieldDescriptor* field,
+                                              const Options& options);
 
  protected:
-  explicit PrimitiveObjFieldGenerator(const FieldDescriptor* descriptor);
+  PrimitiveObjFieldGenerator(const FieldDescriptor* descriptor,
+                             const Options& options);
   virtual ~PrimitiveObjFieldGenerator();
 
  private:
@@ -63,12 +67,13 @@
 };
 
 class RepeatedPrimitiveFieldGenerator : public RepeatedFieldGenerator {
-  friend FieldGenerator* FieldGenerator::Make(const FieldDescriptor* field);
+  friend FieldGenerator* FieldGenerator::Make(const FieldDescriptor* field,
+                                              const Options& options);
 
  protected:
-  explicit RepeatedPrimitiveFieldGenerator(const FieldDescriptor* descriptor);
+  RepeatedPrimitiveFieldGenerator(const FieldDescriptor* descriptor,
+                                  const Options& options);
   virtual ~RepeatedPrimitiveFieldGenerator();
-  virtual void FinishInitialization(void);
 
  private:
   GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(RepeatedPrimitiveFieldGenerator);