diff --git a/libavcodec/cngdec.c b/libavcodec/cngdec.c
index 28432ac719..43b96fea1b 100644
--- a/libavcodec/cngdec.c
+++ b/libavcodec/cngdec.c
@@ -69,7 +69,6 @@ static av_cold int cng_decode_init(AVCodecContext *avctx)
     p->excitation       = av_mallocz_array(avctx->frame_size, sizeof(*p->excitation));
     if (!p->refl_coef || !p->target_refl_coef || !p->lpc_coef ||
         !p->filter_out || !p->excitation) {
-        cng_decode_close(avctx);
         return AVERROR(ENOMEM);
     }
 
@@ -175,4 +174,6 @@ AVCodec ff_comfortnoise_decoder = {
     .sample_fmts    = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
                                                      AV_SAMPLE_FMT_NONE },
     .capabilities   = AV_CODEC_CAP_DELAY | AV_CODEC_CAP_DR1,
+    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE |
+                      FF_CODEC_CAP_INIT_CLEANUP,
 };