diff --git a/src/sugar3/graphics/window.py b/src/sugar3/graphics/window.py
index cda4dc34..510949b7 100644
--- a/src/sugar3/graphics/window.py
+++ b/src/sugar3/graphics/window.py
@@ -20,6 +20,9 @@
 STABLE.
 """
 
+import gi
+gi.require_version('GdkX11', '3.0')
+
 from gi.repository import GObject
 from gi.repository import GLib
 from gi.repository import Gdk