diff --git a/gst/isomp4/qtdemux.c b/gst/isomp4/qtdemux.c
index 036e509c33..99564e828e 100644
--- a/gst/isomp4/qtdemux.c
+++ b/gst/isomp4/qtdemux.c
@@ -317,7 +317,7 @@ struct _QtDemuxStream
   guint32 stts_samples;
   guint32 n_sample_times;
   guint32 stts_sample_index;
-  guint32 stts_time;
+  guint64 stts_time;
   guint32 stts_duration;
   /* stss */
   gboolean stss_present;
@@ -5623,8 +5623,8 @@ done2:
 
     for (i = stream->stts_index; i < n_sample_times; i++) {
       guint32 stts_samples;
-      guint32 stts_duration;
-      guint32 stts_time;
+      gint32 stts_duration;
+      gint64 stts_time;
 
       if (stream->stts_sample_index >= stream->stts_samples
           || !stream->stts_sample_index) {
@@ -5654,7 +5654,9 @@ done2:
         cur->timestamp = stts_time;
         cur->duration = stts_duration;
 
-        stts_time += stts_duration;
+        /* avoid 32-bit wrap-around,
+         * but still mind possible 'negative' duration */
+        stts_time += (gint64) stts_duration;
         cur++;
 
         if (G_UNLIKELY (cur > last)) {