diff --git a/libavcodec/sgidec.c b/libavcodec/sgidec.c
index 02ad1e1165..e954140258 100644
--- a/libavcodec/sgidec.c
+++ b/libavcodec/sgidec.c
@@ -297,4 +297,5 @@ AVCodec ff_sgi_decoder = {
     .decode         = decode_frame,
     .init           = sgi_decode_init,
     .capabilities   = AV_CODEC_CAP_DR1,
+    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
 };