diff --git a/libavformat/dashenc.c b/libavformat/dashenc.c
index 8ddf0f36e6..519f9c4440 100644
--- a/libavformat/dashenc.c
+++ b/libavformat/dashenc.c
@@ -632,6 +632,7 @@ static int dash_write_header(AVFormatContext *s)
         st->sample_aspect_ratio = s->streams[i]->sample_aspect_ratio;
         st->time_base = s->streams[i]->time_base;
         ctx->avoid_negative_ts = s->avoid_negative_ts;
+        ctx->flags = s->flags;
 
         ctx->pb = avio_alloc_context(os->iobuf, sizeof(os->iobuf), AVIO_FLAG_WRITE, os, NULL, dash_write, NULL);
         if (!ctx->pb) {