diff --git a/libavcodec/h264dec.c b/libavcodec/h264dec.c
index f29c3f9048..6a28f3a3ae 100644
--- a/libavcodec/h264dec.c
+++ b/libavcodec/h264dec.c
@@ -626,7 +626,7 @@ static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size)
     }
 
     ret = ff_h2645_packet_split(&h->pkt, buf, buf_size, avctx, h->is_avc,
-                                h->nal_length_size, avctx->codec_id, avctx->flags2 & AV_CODEC_FLAG2_FAST);
+                                h->nal_length_size, avctx->codec_id, 0);
     if (ret < 0) {
         av_log(avctx, AV_LOG_ERROR,
                "Error splitting the input into NAL units.\n");