diff --git a/Data/BDelta.hsc b/Data/BDelta.hsc
--- a/Data/BDelta.hsc
+++ b/Data/BDelta.hsc
@@ -1,4 +1,4 @@
-{-# LANGUAGE ForeignFunctionInterface #-}
+{-# LANGUAGE CPP, ForeignFunctionInterface #-}
 -- |
 -- Module:       Data.BDelta
 -- Copyright:    (c) Joseph Adams 2011
@@ -57,14 +57,14 @@
 import Foreign.C.String (CString, peekCAString)
 import Foreign.C.Types
 
-#if MIN_VERSION_base(4,4,0)
+##if MIN_VERSION_base(4,4,0)
 import Foreign.Marshal.Unsafe (unsafeLocalState)
-#else
+##else
 import System.IO.Unsafe (unsafePerformIO)
 
 unsafeLocalState :: IO a -> a
 unsafeLocalState = unsafePerformIO
-#endif
+##endif
 
 type BDELTAcode = #{type BDELTAcode}
 
diff --git a/bdelta.cabal b/bdelta.cabal
--- a/bdelta.cabal
+++ b/bdelta.cabal
@@ -1,5 +1,5 @@
 Name:                bdelta
-Version:             0.1.1
+Version:             0.1.1.1
 Synopsis:            Simple, fast binary diff/patch
 Description:
     This package has been renamed from bdelta to bytestring-delta, to avoid
@@ -41,7 +41,7 @@
   Exposed-modules:     Data.BDelta
   Build-depends:       base >= 4 && < 5, bytestring
   Build-tools:         hsc2hs
-  Extensions:          ForeignFunctionInterface
+  Extensions:          CPP, ForeignFunctionInterface
   GHC-Options:         -Wall -fno-warn-unused-imports
   C-Sources:           bdelta.c
   Include-Dirs:        .