diff --git a/libavcodec/ulti.c b/libavcodec/ulti.c
index e6fb661f6e..cf6891d530 100644
--- a/libavcodec/ulti.c
+++ b/libavcodec/ulti.c
@@ -428,4 +428,5 @@ AVCodec ff_ulti_decoder = {
     .close          = ulti_decode_end,
     .decode         = ulti_decode_frame,
     .capabilities   = AV_CODEC_CAP_DR1,
+    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
 };