diff --git a/libavcodec/metasound.c b/libavcodec/metasound.c
index be47510d7a..57851a43c5 100644
--- a/libavcodec/metasound.c
+++ b/libavcodec/metasound.c
@@ -382,4 +382,5 @@ const AVCodec ff_metasound_decoder = {
     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF,
     .sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
                                                       AV_SAMPLE_FMT_NONE },
+    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
 };