diff --git a/libavformat/dump.c b/libavformat/dump.c
index 56b37ff7d8..df102e6c65 100644
--- a/libavformat/dump.c
+++ b/libavformat/dump.c
@@ -371,8 +371,8 @@ static void dump_stream_format(AVFormatContext *ic, int i,
         av_cmp_q(st->sample_aspect_ratio, st->codec->sample_aspect_ratio)) {
         AVRational display_aspect_ratio;
         av_reduce(&display_aspect_ratio.num, &display_aspect_ratio.den,
-                  st->codec->width  * st->sample_aspect_ratio.num,
-                  st->codec->height * st->sample_aspect_ratio.den,
+                  st->codec->width  * (int64_t)st->sample_aspect_ratio.num,
+                  st->codec->height * (int64_t)st->sample_aspect_ratio.den,
                   1024 * 1024);
         av_log(NULL, AV_LOG_INFO, ", SAR %d:%d DAR %d:%d",
                st->sample_aspect_ratio.num, st->sample_aspect_ratio.den,