diff --git a/src/darwin/Framework/CHIP/MTRBaseDevice.mm b/src/darwin/Framework/CHIP/MTRBaseDevice.mm
index f21fc5b..a298b29 100644
--- a/src/darwin/Framework/CHIP/MTRBaseDevice.mm
+++ b/src/darwin/Framework/CHIP/MTRBaseDevice.mm
@@ -1894,7 +1894,7 @@
     uint64_t eventTimestampValueSeconds = timeValue / chip::kMillisecondsPerSecond;
     uint64_t eventTimestampValueRemainderMilliseconds = timeValue % chip::kMillisecondsPerSecond;
     NSTimeInterval eventTimestampValueRemainder
-        = NSTimeInterval(eventTimestampValueRemainderMilliseconds / static_cast<uint64_t>(chip::kMillisecondsPerSecond));
+        = NSTimeInterval(eventTimestampValueRemainderMilliseconds) / static_cast<double>(chip::kMillisecondsPerSecond);
     NSTimeInterval eventTimestampValue = eventTimestampValueSeconds + eventTimestampValueRemainder;
 
     return eventTimestampValue;
diff --git a/src/darwin/Framework/CHIP/MTRConversion.h b/src/darwin/Framework/CHIP/MTRConversion.h
index 6f722d0..e576b4f 100644
--- a/src/darwin/Framework/CHIP/MTRConversion.h
+++ b/src/darwin/Framework/CHIP/MTRConversion.h
@@ -38,7 +38,7 @@
 
 inline NSDate * MatterEpochSecondsAsDate(uint32_t matterEpochSeconds)
 {
-    const uint64_t interval = static_cast<uint32_t>(chip::kChipEpochSecondsSinceUnixEpoch) + matterEpochSeconds;
+    const auto interval = static_cast<uint64_t>(chip::kChipEpochSecondsSinceUnixEpoch) + static_cast<uint64_t>(matterEpochSeconds);
     return [NSDate dateWithTimeIntervalSince1970:(NSTimeInterval) interval];
 }