diff --git a/libavcodec/amrwbdec.c b/libavcodec/amrwbdec.c
index 3ff4077f7f..7d1b820bbb 100644
--- a/libavcodec/amrwbdec.c
+++ b/libavcodec/amrwbdec.c
@@ -1303,4 +1303,5 @@ const AVCodec ff_amrwb_decoder = {
     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF,
     .sample_fmts    = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_FLT,
                                                      AV_SAMPLE_FMT_NONE },
+    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
 };