--- mutter-3.16.2/src/core/window.c.orig	2015-05-26 10:52:41.382834963 +0200
+++ mutter-3.16.2/src/core/window.c	2015-05-26 10:53:03.039948034 +0200
@@ -3499,7 +3499,7 @@
 
 static MetaMonitorInfo *
 find_monitor_by_winsys_id (MetaWindow *window,
-                           guint       winsys_id)
+                           gint       winsys_id)
 {
   int i;
 
@@ -3618,7 +3618,7 @@
    */
 
   gboolean did_placement;
-  guint old_output_winsys_id;
+  gint old_output_winsys_id;
   MetaRectangle unconstrained_rect;
   MetaRectangle constrained_rect;
   MetaMoveResizeResultFlags result = 0;