diff --git a/libavformat/oggparsetheora.c b/libavformat/oggparsetheora.c
index 87a676fe482f29a96a8f269d776637619b5bf52f..c481a79d4b7a92fc909fd5407943b33964c217c3 100644
--- a/libavformat/oggparsetheora.c
+++ b/libavformat/oggparsetheora.c
@@ -191,7 +191,7 @@ static int theora_packet(AVFormatContext *s, int idx)
 
         pts = theora_gptopts(s, idx, os->granule, NULL);
         if (pts != AV_NOPTS_VALUE)
-            pts -= duration;
+            pts = av_sat_sub64(pts, duration);
         os->lastpts = os->lastdts = pts;
         if(s->streams[idx]->start_time == AV_NOPTS_VALUE) {
             s->streams[idx]->start_time = os->lastpts;