diff --git a/Text/PrettyPrint/Leijen.hs b/Text/PrettyPrint/Leijen.hs
--- a/Text/PrettyPrint/Leijen.hs
+++ b/Text/PrettyPrint/Leijen.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE CPP #-}
+{-# LANGUAGE OverlappingInstances #-}
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Text.PrettyPrint.Leijen
@@ -14,7 +15,7 @@
 -- @
 --      \"A prettier printer\"
 --      Draft paper, April 1997, revised March 1998.
---      <http://cm.bell-labs.com/cm/cs/who/wadler/papers/prettier/prettier.ps>
+--      <http://homepages.inf.ed.ac.uk/wadler/papers/prettier/prettier.pdf>
 -- @
 --
 -- PPrint is an implementation of the pretty printing combinators
@@ -118,9 +119,15 @@
 import Prelude hiding ((<$>))
 #endif
 
-infixr 5 </>,<//>,<$>,<$$>
-infixr 6 <>,<+>
+#if !MIN_VERSION_base(4,11,0)
+import Data.Monoid (Monoid(..))
+#endif
 
+infixr 5 </>,<//>,<$>,<$$>
+infixr 6 <+>
+#if !MIN_VERSION_base(4,11,0)
+infixr 6 <>
+#endif
 
 -----------------------------------------------------------
 -- list, tupled and semiBraces pretty print a list of
@@ -309,8 +316,17 @@
 -- | The document @(x \<\> y)@ concatenates document @x@ and document
 -- @y@. It is an associative operation having 'empty' as a left and
 -- right unit.  (infixr 6)
+#if MIN_VERSION_base(4,11,0)
+instance Semigroup Doc where
+  x <> y          = x `beside` y
+#else
 (<>) :: Doc -> Doc -> Doc
 x <> y          = x `beside` y
+#endif
+
+instance Monoid Doc where
+  mempty = empty
+  mappend = (<>)
 
 -- | The document @(x \<+\> y)@ concatenates document @x@ and @y@ with a
 -- @space@ in between.  (infixr 6)
diff --git a/wl-pprint.cabal b/wl-pprint.cabal
--- a/wl-pprint.cabal
+++ b/wl-pprint.cabal
@@ -1,5 +1,5 @@
 Name:                wl-pprint
-Version:             1.2
+Version:             1.2.1
 Cabal-Version:       >=1.6
 Synopsis:            The Wadler/Leijen Pretty Printer
 Category:            Text
@@ -10,15 +10,13 @@
 License:             BSD3
 License-file:        LICENSE
 Author:              Daan Leijen
-Maintainer:          Noam Lewis <jones.noamle@gmail.com> 
+Maintainer:          Noam Lewis <jones.noamle@gmail.com>
 Build-Type:          Simple
 
 Library
   Build-Depends:       base < 5
   Exposed-Modules:     Text.PrettyPrint.Leijen
-  Extensions:          OverlappingInstances
 
 source-repository head
   type: git
   location: git@github.com:sinelaw/wl-pprint.git
-