diff --git a/Codec/Compression/Zlib/Internal.hs b/Codec/Compression/Zlib/Internal.hs
--- a/Codec/Compression/Zlib/Internal.hs
+++ b/Codec/Compression/Zlib/Internal.hs
@@ -54,18 +54,16 @@
   decompressWithErrors,
   DecompressStream(..),
   DecompressError(..),
+  foldDecompressStream,
+  fromDecompressStream,
   ) where
 
 import Prelude hiding (length)
 import Control.Monad (when)
 import Control.Exception (assert)
 import qualified Data.ByteString.Lazy as L
-#ifdef BYTESTRING_IN_BASE
-import qualified Data.ByteString.Base as S
-#else
 import qualified Data.ByteString.Lazy.Internal as L
 import qualified Data.ByteString.Internal as S
-#endif
 
 import qualified Codec.Compression.Zlib.Stream as Stream
 import Codec.Compression.Zlib.Stream (Stream)
@@ -139,13 +137,8 @@
 -- are 16k and 32k respectively (less a small accounting overhead).
 --
 defaultCompressBufferSize, defaultDecompressBufferSize :: Int
-#ifdef BYTESTRING_IN_BASE
-defaultCompressBufferSize   = 16 * 1024 - 16
-defaultDecompressBufferSize = 32 * 1024 - 16
-#else
 defaultCompressBufferSize   = 16 * 1024 - L.chunkOverhead
 defaultDecompressBufferSize = 32 * 1024 - L.chunkOverhead
-#endif
 
 -- | A sequence of chunks of data produced from decompression.
 --
@@ -181,7 +174,8 @@
    | DataError
 
 -- | Fold an 'DecompressionStream'. Just like 'foldr' but with an extra error
--- case. For example to convert to a list and translate the errors into exceptions:
+-- case. For example to convert to a list and translate the errors into
+-- exceptions:
 --
 -- > foldDecompressStream (:) [] (\code msg -> error msg)
 --
@@ -194,10 +188,18 @@
     fold (StreamChunk bs stream) = chunk bs (fold stream)
     fold (StreamError code msg)  = err code msg
 
+-- | Convert a 'DecompressStream' to a lazy 'ByteString'. If any decompression
+-- errors are encountered then they are thrown as exceptions.
+--
+-- This is a special case of 'foldDecompressStream'.
+--
 fromDecompressStream :: DecompressStream -> L.ByteString
 fromDecompressStream =
   foldDecompressStream L.Chunk L.Empty
     (\_code msg -> error ("Codec.Compression.Zlib: " ++ msg))
+
+--TODO: throw DecompressError as an Exception class type and document that it
+-- does this.
 
 -- | Compress a data stream.
 --
diff --git a/Codec/Compression/Zlib/Stream.hsc b/Codec/Compression/Zlib/Stream.hsc
--- a/Codec/Compression/Zlib/Stream.hsc
+++ b/Codec/Compression/Zlib/Stream.hsc
@@ -82,15 +82,15 @@
 import Foreign
          ( Word8, Ptr, nullPtr, plusPtr, peekByteOff, pokeByteOff, mallocBytes
          , ForeignPtr, FinalizerPtr, newForeignPtr_, addForeignPtrFinalizer
-	 , finalizeForeignPtr, withForeignPtr, touchForeignPtr
+	 , withForeignPtr, touchForeignPtr
 	 , unsafeForeignPtrToPtr, unsafePerformIO )
+#ifdef __GLASGOW_HASKELL__
+import Foreign
+         ( finalizeForeignPtr )
+#endif
 import Foreign.C
          ( CInt, CUInt, CChar, CString, withCAString, peekCAString )
-#ifdef BYTESTRING_IN_BASE
-import Data.ByteString.Base (nullForeignPtr)
-#else
 import Data.ByteString.Internal (nullForeignPtr)
-#endif
 import System.IO.Unsafe (unsafeInterleaveIO)
 import Control.Monad (liftM)
 import Control.Exception (assert)
@@ -816,7 +816,12 @@
 -- longer be needed, for example if an error occurs or if the stream ends.
 --
 finalise :: Stream ()
+#ifdef __GLASGOW_HASKELL__
+--TODO: finalizeForeignPtr is ghc-only
 finalise = getStreamState >>= unsafeLiftIO . finalizeForeignPtr
+#else
+finalise = return ()
+#endif
 
 checkFormatSupported :: Format -> Stream ()
 checkFormatSupported format = do
diff --git a/LICENSE b/LICENSE
--- a/LICENSE
+++ b/LICENSE
@@ -9,6 +9,7 @@
 2. Redistributions in binary form must reproduce the above copyright
    notice, this list of conditions and the following disclaimer in the
    documentation and/or other materials provided with the distribution.
+3. This clause is intentionally left blank.
 
 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
diff --git a/zlib.cabal b/zlib.cabal
--- a/zlib.cabal
+++ b/zlib.cabal
@@ -1,10 +1,10 @@
 name:            zlib
-version:         0.5.2.0
+version:         0.5.3.1
 copyright:       (c) 2006-2008 Duncan Coutts
 license:         BSD3
 license-file:    LICENSE
-author:          Duncan Coutts <duncan@haskell.org>
-maintainer:      Duncan Coutts <duncan@haskell.org>
+author:          Duncan Coutts <duncan@community.haskell.org>
+maintainer:      Duncan Coutts <duncan@community.haskell.org>
 category:        Codec
 synopsis:        Compression and decompression in the gzip and zlib formats
 description:     This package provides a pure interface for compressing and 
@@ -16,18 +16,17 @@
                  It provides a convenient high level API suitable for most
                  tasks and for the few cases where more control is needed it
                  provides access to the full zlib feature set.
-stability:       provisional
 build-type:      Simple
-cabal-version:   >= 1.2.1
+cabal-version:   >= 1.6
 extra-source-files: cbits/crc32.h cbits/inffast.h cbits/inflate.h
                     cbits/trees.h cbits/deflate.h cbits/inffixed.h
                     cbits/inftrees.h cbits/zutil.h
                     -- demo programs:
                     examples/gzip.hs examples/gunzip.hs
 
-flag bytestring-in-base
-  description: In the ghc-6.6 era the bytestring modules were
-               included in the base package.
+source-repository head
+  type: darcs
+  location: http://code.haskell.org/zlib/
 
 library
   exposed-modules: Codec.Compression.GZip,
@@ -36,13 +35,8 @@
                    Codec.Compression.Zlib.Internal
   other-modules:   Codec.Compression.Zlib.Stream
   extensions:      CPP, ForeignFunctionInterface
-  build-depends: base < 5
-  if flag(bytestring-in-base)
-    -- bytestring was in base-2.0 and 2.1.1
-    build-depends: base >= 2.0 && < 2.2
-    cpp-options: -DBYTESTRING_IN_BASE
-  else
-    build-depends: base < 2.0 || >= 2.2, bytestring >= 0.9
+  build-depends:   base >= 3 && < 5,
+                   bytestring == 0.9.*
   includes:        zlib.h
   ghc-options:     -Wall
   if !os(windows)