diff --git a/libmpdemux/demux_mpg.c b/libmpdemux/demux_mpg.c
index 1ce2e1c228..b43d68a690 100644
--- a/libmpdemux/demux_mpg.c
+++ b/libmpdemux/demux_mpg.c
@@ -575,6 +575,7 @@ static int demux_mpg_read_packet(demuxer_t *demux,int id){
     if(l<len)
       resize_demux_packet(dp, l);
     len = l;
+    if(set_pts)
     dp->pts=pts/90000.0f;
     dp->pos=demux->filepos;
     /*