diff --git a/src/google/protobuf/io/coded_stream.h b/src/google/protobuf/io/coded_stream.h
index 361c406b5b..cb1869a7ca 100644
--- a/src/google/protobuf/io/coded_stream.h
+++ b/src/google/protobuf/io/coded_stream.h
@@ -1035,7 +1035,7 @@ inline const uint8* CodedInputStream::ExpectTagFromArray(
 inline void CodedInputStream::GetDirectBufferPointerInline(const void** data,
                                                            int* size) {
   *data = buffer_;
-  *size = buffer_end_ - buffer_;
+  *size = static_cast<int>(buffer_end_ - buffer_);
 }
 
 inline bool CodedInputStream::ExpectAtEnd() {
@@ -1231,7 +1231,7 @@ inline MessageFactory* CodedInputStream::GetExtensionFactory() {
 }
 
 inline int CodedInputStream::BufferSize() const {
-  return buffer_end_ - buffer_;
+  return static_cast<int>(buffer_end_ - buffer_);
 }
 
 inline CodedInputStream::CodedInputStream(ZeroCopyInputStream* input)
diff --git a/src/google/protobuf/wire_format_lite_inl.h b/src/google/protobuf/wire_format_lite_inl.h
index 991c3d041b..b1c477d1a9 100644
--- a/src/google/protobuf/wire_format_lite_inl.h
+++ b/src/google/protobuf/wire_format_lite_inl.h
@@ -835,12 +835,14 @@ inline int WireFormatLite::EnumSize(int value) {
 }
 
 inline int WireFormatLite::StringSize(const string& value) {
-  return io::CodedOutputStream::VarintSize32(value.size()) +
-         value.size();
+  return static_cast<int>(
+      io::CodedOutputStream::VarintSize32(static_cast<uint32>(value.size())) +
+      value.size());
 }
 inline int WireFormatLite::BytesSize(const string& value) {
-  return io::CodedOutputStream::VarintSize32(value.size()) +
-         value.size();
+  return static_cast<int>(
+      io::CodedOutputStream::VarintSize32(static_cast<uint32>(value.size())) +
+      value.size());
 }