diff --git a/libavformat/riff.c b/libavformat/riff.c
index 6b093b2683..80a1b719ec 100644
--- a/libavformat/riff.c
+++ b/libavformat/riff.c
@@ -40,6 +40,7 @@ const AVCodecTag ff_codec_bmp_tags[] = {
     { CODEC_ID_H263,         MKTAG('L', '2', '6', '3') },
     { CODEC_ID_H263,         MKTAG('V', 'X', '1', 'K') },
     { CODEC_ID_H263,         MKTAG('Z', 'y', 'G', 'o') },
+    { CODEC_ID_H263,         MKTAG('M', '2', '6', '3') },
     { CODEC_ID_H263P,        MKTAG('H', '2', '6', '3') },
     { CODEC_ID_H263I,        MKTAG('I', '2', '6', '3') }, /* intel h263 */
     { CODEC_ID_H261,         MKTAG('H', '2', '6', '1') },