diff --git a/Cheapskate/Parse.hs b/Cheapskate/Parse.hs
index b90d8e5..2925132 100644
--- a/Cheapskate/Parse.hs
+++ b/Cheapskate/Parse.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE CPP #-}
 module Cheapskate.Parse (
          markdown
        ) where
@@ -21,6 +22,12 @@ import Control.Applicative
 import qualified Data.Map as M
 import Data.List (intercalate)
 
+#if MIN_VERSION_mtl(2, 3, 0)
+import Control.Monad (guard, unless, replicateM)
+#else
+#endif
+
+
 import Debug.Trace
 
 -- | Parses the input as a markdown document.  Note that 'Doc' is an instance