diff --git a/check-email.cabal b/check-email.cabal
--- a/check-email.cabal
+++ b/check-email.cabal
@@ -1,7 +1,7 @@
 Name:                check-email
 Category:            Network
 License-File:        LICENSE
-Version:             0.1
+Version:             1.0
 Cabal-version:       >= 1.2
 Build-type:          Simple
 Copyright:           2010 Chris Done
@@ -13,12 +13,12 @@
 Extra-source-files:  cbits/check-mx.h
 
 Library
-  Build-depends:    base >= 4 && < 5, email-validate >= 0.2 && <0.3
+  Build-depends:    base >= 4 && < 5
+                  , bytestring
+                  , email-validate >= 0.2
   Extensions:       ForeignFunctionInterface
   Exposed-Modules:  Network.Email.Check
   Ghc-options:      -Wall
-  Extra-libraries:  gd, png, z, jpeg, m, fontconfig, freetype, expat
-  Includes:         gd.h
   Include-dirs:     cbits
   Install-includes: check-mx.h
   C-sources:        cbits/check-mx.c
diff --git a/src/Network/Email/Check.hsc b/src/Network/Email/Check.hsc
--- a/src/Network/Email/Check.hsc
+++ b/src/Network/Email/Check.hsc
@@ -2,9 +2,12 @@
 
 module Network.Email.Check where
 
-import Foreign.C.Types
-import Text.Email.Validate
+import Data.ByteString (ByteString)
+import qualified Data.ByteString as S
+import qualified Data.ByteString.Char8 as S8
 import Foreign.C
+import Foreign.C.Types
+import Text.Email.Validate (validate,domainPart,EmailAddress)
 
 #include "check-mx.h"
 
@@ -13,13 +16,12 @@
 
 -- | Check to see whether an email is (1) RFC-valid and (2) has an
 -- existant MX record.
-check :: String -> IO (Either String EmailAddress)
+check :: ByteString -> IO (Either String EmailAddress)
 check email = do
   case validate email of
     Left e -> return $ Left $ show e
-    Right e -> do exists <- withCString (domainPart e) checkMx 
+    Right e -> do exists <- S.useAsCString (domainPart e) checkMx
                   if exists /= 0
                      then return $ Right e
                      else return $ Left $ "no MX record exists for domain "
-                                          ++ (domainPart e)
-    
+                                          ++ S8.unpack (domainPart e)