diff --git a/video/frame_encode_metadata_writer.h b/video/frame_encode_metadata_writer.h
index 8847145..541ed98 100644
--- a/video/frame_encode_metadata_writer.h
+++ b/video/frame_encode_metadata_writer.h
@@ -28,7 +28,7 @@
   explicit FrameEncodeMetadataWriter(EncodedImageCallback* frame_drop_callback);
   ~FrameEncodeMetadataWriter();
 
-  void OnEncoderInit(const VideoCodec& codec, bool internal_source);
+  void OnEncoderInit(const VideoCodec& codec, bool internal_source = false);
   void OnSetRates(const VideoBitrateAllocation& bitrate_allocation,
                   uint32_t framerate_fps);