diff --git a/libavformat/matroska.c b/libavformat/matroska.c
index 410e2f40c3..9628abcda1 100644
--- a/libavformat/matroska.c
+++ b/libavformat/matroska.c
@@ -32,6 +32,7 @@ const CodecTags ff_mkv_codec_tags[]={
     {"A_MPEG/L2"        , AV_CODEC_ID_MP2},
     {"A_MPEG/L1"        , AV_CODEC_ID_MP2},
     {"A_MPEG/L3"        , AV_CODEC_ID_MP3},
+    {"A_OPUS"           , AV_CODEC_ID_OPUS},
     {"A_PCM/FLOAT/IEEE" , AV_CODEC_ID_PCM_F32LE},
     {"A_PCM/FLOAT/IEEE" , AV_CODEC_ID_PCM_F64LE},
     {"A_PCM/INT/BIG"    , AV_CODEC_ID_PCM_S16BE},