diff --git a/libavformat/audiointerleave.h b/libavformat/audiointerleave.h
index c948c366fb..b37c8aefbd 100644
--- a/libavformat/audiointerleave.h
+++ b/libavformat/audiointerleave.h
@@ -39,7 +39,6 @@ typedef struct {
 int ff_audio_interleave_init(AVFormatContext *s, const int *samples_per_frame, AVRational time_base);
 void ff_audio_interleave_close(AVFormatContext *s);
 
-int ff_interleave_compare_dts(AVFormatContext *s, AVPacket *next, AVPacket *pkt);
 /**
  * Rechunk audio PCM packets per AudioInterleaveContext->samples_per_frame
  * and interleave them correctly.
diff --git a/libavformat/utils.c b/libavformat/utils.c
index c208bd994f..4f51c26697 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -3000,7 +3000,7 @@ next_non_null:
     *next_point= this_pktl;
 }
 
-int ff_interleave_compare_dts(AVFormatContext *s, AVPacket *next, AVPacket *pkt)
+static int ff_interleave_compare_dts(AVFormatContext *s, AVPacket *next, AVPacket *pkt)
 {
     AVStream *st = s->streams[ pkt ->stream_index];
     AVStream *st2= s->streams[ next->stream_index];