diff --git a/libavformat/flvdec.c b/libavformat/flvdec.c
index 94c9e28334..2e70352c53 100644
--- a/libavformat/flvdec.c
+++ b/libavformat/flvdec.c
@@ -754,6 +754,7 @@ static int flv_get_extradata(AVFormatContext *s, AVStream *st, int size)
     av_freep(&st->codecpar->extradata);
     if (ff_get_extradata(s, st->codecpar, s->pb, size) < 0)
         return AVERROR(ENOMEM);
+    st->internal->need_context_update = 1;
     return 0;
 }

--