diff --git a/snap-server.cabal b/snap-server.cabal
--- a/snap-server.cabal
+++ b/snap-server.cabal
@@ -1,5 +1,5 @@
 name:           snap-server
-version:        0.2.15.1
+version:        0.2.16
 synopsis:       A fast, iteratee-based, epoll-enabled web server for the Snap Framework
 description:
   This is the first developer prerelease of the Snap framework.  Snap is a
@@ -109,6 +109,7 @@
     attoparsec >= 0.8.1 && < 0.9,
     attoparsec-iteratee >= 0.1.1 && <0.2,
     base >= 4 && < 5,
+    binary >=0.5 && <0.6,
     bytestring,
     bytestring-nums,
     bytestring-show >= 0.3.2 && < 0.4,
@@ -122,12 +123,13 @@
     murmur-hash >= 0.1 && < 0.2,
     network == 2.2.1.*,
     old-locale,
-    snap-core == 0.2.15.1,
+    snap-core == 0.2.16,
     template-haskell,
     time,
     transformers,
     unix-compat,
-    vector >= 0.7 && <0.8
+    vector >= 0.7 && <0.8,
+    vector-algorithms >= 0.3.4 && <0.4
 
   if flag(portable) || os(windows)
     cpp-options: -DPORTABLE
diff --git a/src/Snap/Internal/Http/Server.hs b/src/Snap/Internal/Http/Server.hs
--- a/src/Snap/Internal/Http/Server.hs
+++ b/src/Snap/Internal/Http/Server.hs
@@ -13,6 +13,7 @@
 import           Control.Exception
 import           Data.Char
 import           Data.CIByteString
+import           Data.Binary.Put
 import           Data.ByteString (ByteString)
 import qualified Data.ByteString as S
 import qualified Data.ByteString.Char8 as SC
@@ -41,7 +42,7 @@
 import           Snap.Internal.Http.Parser
 import           Snap.Internal.Http.Server.Date
 import           Snap.Internal.Iteratee.Debug
-import           Snap.Iteratee hiding (foldl', head, take, FileOffset)
+import           Snap.Iteratee hiding (foldl', head, take, mapM_, FileOffset)
 import qualified Snap.Iteratee as I
 
 #ifdef LIBEV
@@ -420,12 +421,13 @@
   where
     go = do
         let (major,minor) = rqVersion req
-        let hl = [ "HTTP/"
-                 , bsshow major
-                 , "."
-                 , bsshow minor
-                 , " 100 Continue\r\n\r\n" ]
-        iter <- liftIO $ enumBS (S.concat hl) writeEnd
+        let hl = runPut $ do
+                     putByteString "HTTP/"
+                     showp major
+                     putAscii '.'
+                     showp minor
+                     putByteString " 100 Continue\r\n\r\n"
+        iter <- liftIO $ enumLBS hl writeEnd
         liftIO $ run iter
 
 
@@ -660,15 +662,17 @@
 
 
     --------------------------------------------------------------------------
-    fmtHdrs hdrs =
-        {-# SCC "fmtHdrs" #-}
-        concat xs
+    putHdrs hdrs =
+        {-# SCC "putHdrs" #-}
+        mapM_ putHeader $ Map.toList hdrs
       where
-        xs = map f $ Map.toList hdrs
-
-        f (k, ys) = map (g k) ys
+        putHeader (k, ys) = mapM_ (putOne k) ys
 
-        g k y = S.concat [ unCI k, ": ", y, "\r\n" ]
+        putOne k y = do
+            putByteString $ unCI k
+            putByteString ": "
+            putByteString y
+            putByteString "\r\n"
 
 
     --------------------------------------------------------------------------
@@ -759,24 +763,22 @@
 
     --------------------------------------------------------------------------
     mkHeaderString :: Response -> ByteString
-    mkHeaderString r =
-        {-# SCC "mkHeaderString" #-}
-        S.concat $ concat [hl, hdr, eol]
+    mkHeaderString r = out
       where
-        hl = [ "HTTP/"
-             , bsshow major
-             , "."
-             , bsshow minor
-             , " "
-             , bsshow $ rspStatus r
-             , " "
-             , rspStatusReason r
-             , "\r\n" ]
-
-        hdr = fmtHdrs $ headers r
-
-        eol = ["\r\n"]
-
+        !out = {-# SCC "mkHeaderString" #-}
+               S.concat $ L.toChunks $ runPut $ do
+                   putByteString "HTTP/"
+                   showp major
+                   putAscii '.'
+                   showp minor
+                   putAscii ' '
+                   showp $ rspStatus r
+                   putAscii ' '
+                   putByteString $ rspStatusReason r
+                   putByteString "\r\n"
+                   putHdrs $ headers r
+                   putByteString "\r\n"
+                   
 
 ------------------------------------------------------------------------------
 checkConnectionClose :: (Int, Int) -> Headers -> ServerMonad ()
@@ -816,10 +818,5 @@
 ------------------------------------------------------------------------------
 toBS :: String -> ByteString
 toBS = S.pack . map c2w
-
-
---------------------------------------------------------------------------
-bsshow :: (Show a) => a -> ByteString
-bsshow = l2s . show
 
 
diff --git a/test/pongserver/Main.hs b/test/pongserver/Main.hs
--- a/test/pongserver/Main.hs
+++ b/test/pongserver/Main.hs
@@ -26,5 +26,6 @@
 
   where
     go m = do
-        httpServe "*" 3000 "localhost" Nothing Nothing pongServer 
+        httpServe "*" 3000 "localhost" (Just "foo.log") Nothing pongServer 
+        --httpServe "*" 3000 "localhost" Nothing Nothing pongServer 
         putMVar m ()
diff --git a/test/snap-server-testsuite.cabal b/test/snap-server-testsuite.cabal
--- a/test/snap-server-testsuite.cabal
+++ b/test/snap-server-testsuite.cabal
@@ -47,7 +47,8 @@
      test-framework-quickcheck2 >= 0.2.6 && < 0.3,
      time,
      transformers,
-     vector >= 0.7 && <0.8
+     vector >= 0.7 && <0.8,
+     vector-algorithms >= 0.3.4 && <0.4
 
    if !os(windows)
      build-depends: unix
@@ -103,8 +104,10 @@
      time,
      transformers,
      unix-compat,
-     vector >= 0.7 && <0.8
+     vector >= 0.7 && <0.8,
+     vector-algorithms >= 0.3.4 && <0.4
 
+
    if flag(portable) || os(windows)
      cpp-options: -DPORTABLE
    else
@@ -182,7 +185,9 @@
      test-framework-quickcheck2 >= 0.2.6 && < 0.3,
      time,
      transformers,
-     vector >= 0.7 && <0.8
+     vector >= 0.7 && <0.8,
+     vector-algorithms >= 0.3.4 && <0.4
+
 
    if !os(windows)
      build-depends: unix