diff --git a/hack2-handler-happstack-server.cabal b/hack2-handler-happstack-server.cabal
--- a/hack2-handler-happstack-server.cabal
+++ b/hack2-handler-happstack-server.cabal
@@ -1,5 +1,5 @@
 Name:                 hack2-handler-happstack-server
-Version:              2011.6.19
+Version:              2011.6.20
 Build-type:           Simple
 Synopsis:             Hack2 Happstack server handler
 Description:          Hack2 Happstack server handler
@@ -21,7 +21,7 @@
                     , network
                     , bytestring
                     , data-default >= 0.2
-                    , hack2 >= 2011.6.19
+                    , hack2 >= 2011.6.20
                     , happstack-server < 6
                     , containers
                     , mtl
diff --git a/src/Hack2/Handler/HappstackServer.hs b/src/Hack2/Handler/HappstackServer.hs
--- a/src/Hack2/Handler/HappstackServer.hs
+++ b/src/Hack2/Handler/HappstackServer.hs
@@ -61,14 +61,14 @@
     reqToEnv req =
       def
         { Hack2.requestMethod   = convertRequestMethod $ rqMethod req
-        , Hack2.scriptName      = L.empty
-        , Hack2.pathInfo        = L.pack $ escape $ "/" ++ (intercalate "/" $ rqPaths req)
-        , Hack2.queryString     = L.pack $ escape $ dropWhile (== '?') $ rqQuery req
-        , Hack2.serverName      = serverName conf
+        , Hack2.scriptName      = S.empty
+        , Hack2.pathInfo        = S.pack $ escape $ "/" ++ (intercalate "/" $ rqPaths req)
+        , Hack2.queryString     = S.pack $ escape $ dropWhile (== '?') $ rqQuery req
+        , Hack2.serverName      = l2s $ serverName conf
         , Hack2.serverPort      = (snd $ rqPeer req)
         , Hack2.httpHeaders     = headersToHttp (rqHeaders req)
         , Hack2.hackInput       = Hack2.HackEnumerator $ toEnumerator $ (\(Body x) -> x) (rqBody req)
-        , Hack2.hackHeaders     = [("RemoteHost", L.pack $ fst $ rqPeer req)]
+        , Hack2.hackHeaders     = [("RemoteHost", S.pack $ fst $ rqPeer req)]
         }
     
     escape = escapeURIString isAllowedInURI
@@ -83,11 +83,11 @@
     convertRequestMethod Happstack.CONNECT     =     Hack2.CONNECT
     
 
-headersToHttp :: Headers -> [(L.ByteString, L.ByteString)]
+headersToHttp :: Headers -> [(S.ByteString, S.ByteString)]
 headersToHttp = M.toList >>> map snd >>> map headerToPair
   where
     headerToPair (HeaderPair k v) = 
-      (L.pack $ normalizeHeader $ S.unpack k, s2l $ S.intercalate " " v)
+      (S.pack $ normalizeHeader $ S.unpack k, S.intercalate " " v)
 
 hackRToServerPartR :: Hack2.Response -> IO Happstack.Response
 hackRToServerPartR r = do
@@ -107,11 +107,11 @@
 s2l :: S.ByteString -> L.ByteString
 s2l = L.fromChunks . return
 
-httpToHeaders :: [(L.ByteString, L.ByteString)] -> Headers
+httpToHeaders :: [(S.ByteString, S.ByteString)] -> Headers
 httpToHeaders = map pairToHeader >>> M.fromList
   where 
     pairToHeader (k,v) = 
-      ((S.pack $ map toLower $ L.unpack k), HeaderPair (l2s k) [l2s v])
+      ((S.pack $ map toLower $ S.unpack k), HeaderPair (k) [v])
 
 
 -- happstack converts all request header to lowercase ...