diff --git a/libavformat/matroska.c b/libavformat/matroska.c
index 3e4b6e9778..591530490c 100644
--- a/libavformat/matroska.c
+++ b/libavformat/matroska.c
@@ -213,6 +213,7 @@ static CodecTags codec_tags[]={
     {"V_REAL/RV20"      , CODEC_ID_RV20},
     {"V_REAL/RV30"      , CODEC_ID_RV30},
     {"V_REAL/RV40"      , CODEC_ID_RV40},
+    {"V_THEORA"         , CODEC_ID_THEORA},
 /* TODO: Real/Quicktime */
 
 //    {"A_MS/ACM"         , CODEC_ID_NONE},