diff --git a/libavformat/isom.c b/libavformat/isom.c
index 5a69e075a2..92bba56536 100644
--- a/libavformat/isom.c
+++ b/libavformat/isom.c
@@ -110,7 +110,6 @@ const AVCodecTag codec_movvideo_tags[] = {
     { CODEC_ID_MPEG2VIDEO, MKTAG('m', 'x', '3', 'n') }, /* MPEG2 IMX NTSC 525/60 30mb/s produced by FCP */
     { CODEC_ID_MPEG2VIDEO, MKTAG('m', 'x', '3', 'p') }, /* MPEG2 IMX PAL 625/50 30mb/s produced by FCP */
     { CODEC_ID_MPEG2VIDEO, MKTAG('A', 'V', 'm', 'p') }, /* AVID IMX PAL */
-    { CODEC_ID_MPEG2VIDEO, MKTAG('A', 'V', 'm', 'n') }, /* AVID IMX NTSC */
 
   //{ CODEC_ID_JPEG2000, MKTAG('m', 'j', 'p', '2') }, /* JPEG 2000 produced by FCP */