diff --git a/demux/demux_lavf.c b/demux/demux_lavf.c
index ed4d1a21f5a6f..ce9238d51f928 100644
--- a/demux/demux_lavf.c
+++ b/demux/demux_lavf.c
@@ -1153,8 +1153,8 @@ static int demux_open_lavf(demuxer_t *demuxer, enum demux_check check)
     // We initially prefer track durations over container durations because they
     // have a higher degree of precision over the container duration which are
     // only accurate to the 6th decimal place. This is probably a lavf bug.
-    double total_duration = 0;
-    double av_duration = 0;
+    double total_duration = -1;
+    double av_duration = -1;
     for (int n = 0; n < priv->avfc->nb_streams; n++) {
         AVStream *st = priv->avfc->streams[n];
         if (st->duration <= 0)
@@ -1166,7 +1166,7 @@ static int demux_open_lavf(demuxer_t *demuxer, enum demux_check check)
             av_duration = MPMAX(av_duration, f_duration);
     }
     double duration = av_duration > 0 ? av_duration : total_duration;
-    if (duration == 0 && priv->avfc->duration > 0)
+    if (duration < 0 && priv->avfc->duration > 0)
         duration = (double)priv->avfc->duration / AV_TIME_BASE;
     demuxer->duration = duration;