diff --git a/libavformat/nutenc.c b/libavformat/nutenc.c
index a4b776522d..d227c9a314 100644
--- a/libavformat/nutenc.c
+++ b/libavformat/nutenc.c
@@ -697,6 +697,9 @@ static int nut_write_header(AVFormatContext *s){
     if ((ret = write_headers(s, bc)) < 0)
         return ret;
 
+    if (s->avoid_negative_ts < 0)
+        s->avoid_negative_ts = 1;
+
     avio_flush(bc);
 
     return 0;