diff --git a/include/grpcpp/impl/codegen/proto_utils.h b/include/grpcpp/impl/codegen/proto_utils.h
index 2cf4cdcc9b5..2e102135a36 100644
--- a/include/grpcpp/impl/codegen/proto_utils.h
+++ b/include/grpcpp/impl/codegen/proto_utils.h
@@ -49,7 +49,7 @@ Status GenericSerialize(const grpc::protobuf::MessageLite& msg, ByteBuffer* bb,
                 "ProtoBufferWriter must be a subclass of "
                 "::protobuf::io::ZeroCopyOutputStream");
   *own_buffer = true;
-  int byte_size = msg.ByteSize();
+  int byte_size = msg.ByteSizeLong();
   if ((size_t)byte_size <= GRPC_SLICE_INLINED_SIZE) {
     Slice slice(byte_size);
     // We serialize directly into the allocated slices memory