diff --git a/hw/dmx/dmxcursor.c b/hw/dmx/dmxcursor.c
index 1a77c7d78..35aca81b4 100644
--- a/hw/dmx/dmxcursor.c
+++ b/hw/dmx/dmxcursor.c
@@ -346,6 +346,8 @@ dmxComputeScreenOrigins(void)
             screenInfo.screens[i]->y -= minY;
         }
     }
+
+    update_desktop_dimensions();
 }
 
 /** Recompute origin information in the #dmxScreens list.  This is