diff --git a/libavformat/dv.c b/libavformat/dv.c
index f972478f69..4a32dd1e47 100644
--- a/libavformat/dv.c
+++ b/libavformat/dv.c
@@ -288,7 +288,7 @@ static int dv_extract_video_info(DVDemuxContext *c, uint8_t *frame)
 
         avpriv_set_pts_info(c->vst, 64, c->sys->time_base.num,
                             c->sys->time_base.den);
-        avctx->time_base = c->sys->time_base;
+        c->vst->avg_frame_rate = av_inv_q(c->vst->time_base);
 
         /* finding out SAR is a little bit messy */
         vsc_pack = dv_extract_pack(frame, dv_video_control);