diff --git a/binary-strict.cabal b/binary-strict.cabal
--- a/binary-strict.cabal
+++ b/binary-strict.cabal
@@ -1,5 +1,5 @@
 name:            binary-strict
-version:         0.4.8
+version:         0.4.8.1
 license:         BSD3
 license-file:    LICENSE
 author:          Lennart Kolmodin <kolmodin@dtek.chalmers.se>
@@ -14,7 +14,7 @@
 		 documentation.
 synopsis:        Binary deserialisation using strict ByteStrings
 category:        Data, Parsing
-build-depends:   base<5, containers, array, bytestring>=0.9, mtl
+build-depends:   base<5, containers, array, bytestring>=0.9
 stability:       provisional
 tested-with:     GHC == 6.8.2
 exposed-modules: Data.Binary.BitPut
@@ -31,3 +31,4 @@
 extra-source-files: tests/BitGetTest.hs, src/Data/Binary/Strict/Common.h
 ghc-options:     -Wall -fno-warn-name-shadowing
 build-type:      Simple
+build-depends:   mtl >= 2.1 && <2.2
diff --git a/src/Data/Binary/BitBuilder.hs b/src/Data/Binary/BitBuilder.hs
--- a/src/Data/Binary/BitBuilder.hs
+++ b/src/Data/Binary/BitBuilder.hs
@@ -37,9 +37,9 @@
 
 import Foreign
 import Data.Monoid
-import Data.Word
 import qualified Data.ByteString      as S
 import qualified Data.ByteString.Lazy as L
+import System.IO.Unsafe (unsafePerformIO)
 
 #ifdef BYTESTRING_IN_BASE
 import Data.ByteString.Base (inlinePerformIO)