diff --git a/libavformat/internal.h b/libavformat/internal.h
index 6c026f08a0..489a7cad08 100644
--- a/libavformat/internal.h
+++ b/libavformat/internal.h
@@ -660,15 +660,6 @@ int ff_is_intra_only(enum AVCodecID id);
  */
 enum AVCodecID ff_get_pcm_codec_id(int bps, int flt, int be, int sflags);
 
-/**
- * Copy side data from source to destination stream
- *
- * @param dst pointer to destination AVStream
- * @param src pointer to source AVStream
- * @return >=0 on success, AVERROR code on error
- */
-int ff_stream_side_data_copy(AVStream *dst, const AVStream *src);
-
 /**
  * Create a new stream and copy to it all parameters from a source stream, with
  * the exception of the index field, which is set when the new stream is