diff --git a/fftools/ffmpeg_demux.c b/fftools/ffmpeg_demux.c
index a6df2a1904..40bbfa0c0e 100644
--- a/fftools/ffmpeg_demux.c
+++ b/fftools/ffmpeg_demux.c
@@ -1286,7 +1286,6 @@ static void dump_attachment(InputStream *ist, const char *filename)
     }
 
     avio_write(out, st->codecpar->extradata, st->codecpar->extradata_size);
-    avio_flush(out);
     avio_close(out);
 }