diff --git a/libavcodec/sonic.c b/libavcodec/sonic.c
index 2ed57586c8..74b388c64f 100644
--- a/libavcodec/sonic.c
+++ b/libavcodec/sonic.c
@@ -1080,7 +1080,7 @@ const AVCodec ff_sonic_decoder = {
     .close          = sonic_decode_close,
     .decode         = sonic_decode_frame,
     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_EXPERIMENTAL | AV_CODEC_CAP_CHANNEL_CONF,
-    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
+    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
 };
 #endif /* CONFIG_SONIC_DECODER */