diff --git a/ges/ges-track-transition.c b/ges/ges-track-transition.c
index c273167767..708b6549f6 100644
--- a/ges/ges-track-transition.c
+++ b/ges/ges-track-transition.c
@@ -181,6 +181,7 @@ ges_track_transition_dispose (GObject * object)
 
   if (self->vsmpte) {
     g_object_unref (self->vsmpte);
+    self->vsmpte = NULL;
   }
 
   G_OBJECT_CLASS (ges_track_transition_parent_class)->dispose (object);