diff --git a/libavformat/utils.c b/libavformat/utils.c
index 7bd815c3d0..af2575aa51 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -1140,7 +1140,7 @@ static void compute_pkt_fields(AVFormatContext *s, AVStream *st,
         }
     }
 
-    if(pkt->pts != AV_NOPTS_VALUE && delay <= MAX_REORDER_DELAY){
+    if(pkt->pts != AV_NOPTS_VALUE && delay <= MAX_REORDER_DELAY && has_decode_delay_been_guessed(st)){
         st->pts_buffer[0]= pkt->pts;
         for(i=0; i<delay && st->pts_buffer[i] > st->pts_buffer[i+1]; i++)
             FFSWAP(int64_t, st->pts_buffer[i], st->pts_buffer[i+1]);