diff --git a/NewBinary.cabal b/NewBinary.cabal
--- a/NewBinary.cabal
+++ b/NewBinary.cabal
@@ -1,5 +1,5 @@
 Name: NewBinary
-Version: 0.1.1
+Version: 0.2.1
 License: OtherLicense
 License-File: LICENSE
 Maintainer: jeremy@n-heptane.com
@@ -8,7 +8,8 @@
 Description: An older binary serialization library used by a number of
  projects. For new projects consider an alternative such as 'binary'.
 Build-Type: Simple
+Cabal-version: >= 1.2.3
 Extensions: CPP, UnboxedTuples, MagicHash
-Build-Depends: base, array
+Build-Depends: base <= 4, array, integer
 Exposed-modules: NewBinary.FastMutInt, NewBinary.Binary
 extra-source-files: todo.txt, Notes
diff --git a/NewBinary/Binary.hs b/NewBinary/Binary.hs
--- a/NewBinary/Binary.hs
+++ b/NewBinary/Binary.hs
@@ -1,4 +1,4 @@
-{-# OPTIONS -cpp #-}
+{-# LANGUAGE CPP, MagicHash #-}
 --
 -- (c) The University of Glasgow 2002
 --
@@ -66,6 +66,7 @@
 import GHC.Exts
 import GHC.IOBase
 import GHC.Real
+import GHC.Integer.Internals    
 import Data.Array.IO 		( IOUArray )
 import Data.Bits
 import Data.Int