diff --git a/libavformat/dxa.c b/libavformat/dxa.c
index 27fa6afb6a..909c5ba2ba 100644
--- a/libavformat/dxa.c
+++ b/libavformat/dxa.c
@@ -143,7 +143,7 @@ static int dxa_read_header(AVFormatContext *s)
     c->readvid = !c->has_sound;
     c->vidpos  = avio_tell(pb);
     s->start_time = 0;
-    s->duration = (int64_t)c->frames * AV_TIME_BASE * num / den;
+    s->duration = av_rescale(c->frames, AV_TIME_BASE * (int64_t)num, den);
     av_log(s, AV_LOG_DEBUG, "%d frame(s)\n",c->frames);
 
     return 0;