diff --git a/libavcodec/vmnc.c b/libavcodec/vmnc.c
index d65e8dc4e5..645a2f5758 100644
--- a/libavcodec/vmnc.c
+++ b/libavcodec/vmnc.c
@@ -582,4 +582,5 @@ const AVCodec ff_vmnc_decoder = {
     .close          = decode_end,
     .decode         = decode_frame,
     .capabilities   = AV_CODEC_CAP_DR1,
+    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
 };