diff --git a/libavcodec/yuv4dec.c b/libavcodec/yuv4dec.c
index f89f62debe..3fb1dbac28 100644
--- a/libavcodec/yuv4dec.c
+++ b/libavcodec/yuv4dec.c
@@ -81,4 +81,5 @@ AVCodec ff_yuv4_decoder = {
     .init         = yuv4_decode_init,
     .decode       = yuv4_decode_frame,
     .capabilities = AV_CODEC_CAP_DR1,
+    .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
 };