--- a/xmonad-contrib.cabal
+++ b/xmonad-contrib.cabal
@@ -63,7 +63,7 @@
                    random,
                    mtl >= 1 && < 3,
                    unix,
-                   X11>=1.6.1 && < 1.9,
+                   X11>=1.6.1 && < 1.10,
                    xmonad>=0.13   && < 0.14,
                    utf8-string
 
