diff --git a/libvo/x11_common.c b/libvo/x11_common.c
index ed84a69c40..efe4406f08 100644
--- a/libvo/x11_common.c
+++ b/libvo/x11_common.c
@@ -1572,6 +1572,8 @@ void xscreensaver_heartbeat(void)
     unsigned int time = GetTimerMS();
     XEvent ev;
 
+    if (mDisplay)
+        xs_windowid = find_xscreensaver_window(mDisplay);
     if (mDisplay && xs_windowid &&
         ((time - time_last) > 30000 || (time - time_last) < 0))
     {