Properly terminate method array.
diff --git a/php/ext/google/protobuf/def.c b/php/ext/google/protobuf/def.c
index ac24400..3f7590c 100644
--- a/php/ext/google/protobuf/def.c
+++ b/php/ext/google/protobuf/def.c
@@ -1036,6 +1036,7 @@
 static zend_function_entry InternalDescriptorPool_methods[] = {
   PHP_ME(InternalDescriptorPool, getGeneratedPool, NULL,
          ZEND_ACC_PUBLIC|ZEND_ACC_STATIC)
+  ZEND_FE_END
 };
 
 // -----------------------------------------------------------------------------