diff --git a/libavcodec/hcom.c b/libavcodec/hcom.c
index 1c49988b3a..3030e37d46 100644
--- a/libavcodec/hcom.c
+++ b/libavcodec/hcom.c
@@ -144,5 +144,5 @@ const AVCodec ff_hcom_decoder = {
     .close          = hcom_close,
     .decode         = hcom_decode,
     .capabilities   = AV_CODEC_CAP_DR1,
-    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
+    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
 };