diff --git a/libavformat/isom.c b/libavformat/isom.c
index 5421875383b814d9de2ed6b83bc403d684def627..901a8b3ff8b8cf3d31cb15220220f4470bb6beb7 100644
--- a/libavformat/isom.c
+++ b/libavformat/isom.c
@@ -171,6 +171,7 @@ const AVCodecTag codec_movaudio_tags[] = {
 
 const AVCodecTag ff_codec_movsubtitle_tags[] = {
     { CODEC_ID_MOV_TEXT, MKTAG('t', 'e', 'x', 't') },
+    { CODEC_ID_MOV_TEXT, MKTAG('t', 'x', '3', 'g') },
     { CODEC_ID_NONE, 0 },
 };