diff --git a/XMonad/Core.hs b/XMonad/Core.hs
index 253e3fe..d7ea521 100644
--- a/XMonad/Core.hs
+++ b/XMonad/Core.hs
@@ -1,5 +1,5 @@
 {-# LANGUAGE ExistentialQuantification, FlexibleInstances, GeneralizedNewtypeDeriving,
-             MultiParamTypeClasses, TypeSynonymInstances #-}
+             MultiParamTypeClasses, TypeSynonymInstances, CPP #-}
 -- required for deriving Typeable
 {-# OPTIONS_GHC -fglasgow-exts #-}