diff --git a/Data/Bson.hs b/Data/Bson.hs
--- a/Data/Bson.hs
+++ b/Data/Bson.hs
@@ -2,7 +2,7 @@
 
 Use the GHC language extension /OverloadedStrings/ to automatically convert String literals to UString (UTF8) -}
 
-{-# LANGUAGE OverloadedStrings, TypeSynonymInstances, FlexibleInstances, DeriveDataTypeable, RankNTypes, OverlappingInstances, IncoherentInstances, ScopedTypeVariables #-}
+{-# LANGUAGE OverloadedStrings, TypeSynonymInstances, FlexibleInstances, DeriveDataTypeable, RankNTypes, OverlappingInstances, IncoherentInstances, ScopedTypeVariables, ForeignFunctionInterface #-}
 
 module Data.Bson (
 	UString,
@@ -35,11 +35,17 @@
 import Data.Digest.OpenSSL.MD5 (md5sum)
 import Numeric (readHex, showHex)
 import Network.BSD (getHostName)
-import System.Posix.Process (getProcessID)
 import System.IO.Unsafe (unsafePerformIO)
 import Data.IORef
 import Data.Maybe (maybeToList, mapMaybe)
 import Control.Monad.Identity
+
+getProcessID :: IO Int
+-- ^ Get the current process id.
+getProcessID = c_getpid
+
+foreign import ccall unsafe "getpid"
+   c_getpid :: IO Int
 
 roundTo :: (RealFrac a) => a -> a -> a
 -- ^ Round second number to nearest multiple of first number. Eg: roundTo (1/1000) 0.12345 = 0.123
diff --git a/bson.cabal b/bson.cabal
--- a/bson.cabal
+++ b/bson.cabal
@@ -1,5 +1,5 @@
 Name: bson
-Version: 0.1
+Version: 0.1.1
 Synopsis: BSON documents are JSON-like objects with a standard binary encoding
 Description: A BSON Document is an untyped (dynamically type-checked) record. I.e. it is a list of name-value pairs, where a Value is a single sum type with constructors for basic types (Bool, Int, Float, String, and Time), compound types (List, and (embedded) Document), and special types (Binary, Javascript, ObjectId, RegEx, and a few others).
 	.
@@ -10,6 +10,6 @@
 Maintainer: Tony Hannan <tony@10gen.com>
 License: OtherLicense
 License-file: LICENSE
-Build-Depends: base < 5, time, bytestring, unix, network, nano-md5, binary, data-binary-ieee754, compact-string-fix, mtl >= 2
+Build-Depends: base < 5, time, bytestring, network, nano-md5, binary, data-binary-ieee754, compact-string-fix, mtl >= 2
 Build-Type: Simple
 Exposed-modules: Data.UString, Data.Bson, Data.Bson.Binary