diff --git a/checkers.cabal b/checkers.cabal
--- a/checkers.cabal
+++ b/checkers.cabal
@@ -1,5 +1,5 @@
 Name:                checkers
-Version:             0.2
+Version:             0.2.2
 Cabal-Version:       >= 1.2
 Synopsis:            Check properties on standard classes and data structures.
 Category:            Testing
@@ -26,7 +26,7 @@
 Library
   hs-Source-Dirs:      src
   Extensions:
-  Build-Depends:       base, random, QuickCheck>=2, array >= 0.1
+  Build-Depends:       base<=4, random, QuickCheck>=2, array >= 0.1
   Exposed-Modules:     
                        Test.QuickCheck.Utils
                        Test.QuickCheck.Checkers
diff --git a/src/Test/QuickCheck/Instances/Word.hs b/src/Test/QuickCheck/Instances/Word.hs
--- a/src/Test/QuickCheck/Instances/Word.hs
+++ b/src/Test/QuickCheck/Instances/Word.hs
@@ -27,3 +27,10 @@
 
 instance CoArbitrary Word8 where
   coarbitrary = variant . (fromIntegral :: Word8 -> Int)
+
+
+instance Arbitrary Word where
+  arbitrary   = fromInteger <$> arbitrary
+
+instance CoArbitrary Word where
+  coarbitrary = variant . (fromIntegral :: Word -> Int)