diff -ru orig/Control/Exception/Peel.hs new/Control/Exception/Peel.hs
--- orig/Control/Exception/Peel.hs	2013-12-09 18:35:35.592693947 +0200
+++ new/Control/Exception/Peel.hs	2013-12-09 18:35:35.000000000 +0200
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE ExistentialQuantification #-}
 
 {- |
@@ -20,7 +21,9 @@
   handle, handleJust,
   try, tryJust,
   evaluate,
+#if !MIN_VERSION_base(4, 7, 0)
   block, unblock,
+#endif
   bracket, bracket_, bracketOnError,
   finally, onException,
   ) where
@@ -108,6 +111,7 @@
 evaluate :: MonadIO m => a -> m a
 evaluate = liftIO . E.evaluate
 
+#if !MIN_VERSION_base(4, 7, 0)
 -- |Generalized version of 'E.block'.
 block :: MonadPeelIO m => m a -> m a
 block = liftIOOp_ E.block
@@ -115,6 +119,7 @@
 -- |Generalized version of 'E.unblock'.
 unblock :: MonadPeelIO m => m a -> m a
 unblock = liftIOOp_ E.unblock
+#endif
 
 -- |Generalized version of 'E.bracket'.  Note, any monadic side
 -- effects in @m@ of the \"release\" computation will be discarded; it