diff --git a/libavformat/movenc.c b/libavformat/movenc.c
index b4c1db2774..f907f67752 100644
--- a/libavformat/movenc.c
+++ b/libavformat/movenc.c
@@ -1244,8 +1244,7 @@ static int mov_write_chnl_tag(AVFormatContext *s, AVIOContext *pb, MOVTrack *tra
     if (config) {
         avio_wb64(pb, 0);
     } else {
-        for (int i = 0; i < layout->nb_channels; i++)
-            avio_w8(pb, speaker_pos[i]);
+        avio_write(pb, speaker_pos, layout->nb_channels);
         av_freep(&speaker_pos);
     }