diff --git a/yesod-core/Yesod/Core/Class/Handler.hs b/yesod-core/Yesod/Core/Class/Handler.hs
index e2577b3d..a8b4504d 100644
--- a/yesod-core/Yesod/Core/Class/Handler.hs
+++ b/yesod-core/Yesod/Core/Class/Handler.hs
@@ -13,8 +13,8 @@ module Yesod.Core.Class.Handler
 import Yesod.Core.Types
 import Data.Monoid (mempty)
 import Control.Monad (liftM)
-import Control.Monad.IO.Class (MonadIO, liftIO)
-import Control.Monad.Trans.Resource (MonadResource, MonadResourceBase, ExceptionT (..))
+import Control.Monad.IO.Class (liftIO)
+import Control.Monad.Trans.Resource (MonadResource, MonadResourceBase)
 import Control.Monad.Trans.Class (lift)
 import Data.Monoid (Monoid)
 import Data.Conduit.Internal (Pipe, ConduitM)
diff --git a/yesod-core/Yesod/Core/Class/Yesod.hs b/yesod-core/Yesod/Core/Class/Yesod.hs
index 8ccc4869..25a11146 100644
--- a/yesod-core/Yesod/Core/Class/Yesod.hs
+++ b/yesod-core/Yesod/Core/Class/Yesod.hs
@@ -39,10 +39,8 @@ import qualified Network.Wai                        as W
 import           Data.Default                       (def)
 import           Network.Wai.Parse                  (lbsBackEnd,
                                                      tempFileBackEnd)
-import           System.IO                          (stdout)
 import           Network.Wai.Logger                 (ZonedDate, clockDateCacher)
 import           System.Log.FastLogger
-import qualified GHC.IO.FD
 import           Text.Blaze                         (customAttribute, textTag,
                                                      toValue, (!))
 import           Text.Blaze                         (preEscapedToMarkup)
@@ -210,9 +208,9 @@ class RenderRoute site => Yesod site where
     -- Default: Sends to stdout and automatically flushes on each write.
     makeLogger :: site -> IO Logger
     makeLogger _ = do
-        loggerSet <- newLoggerSet defaultBufSize Nothing
+        loggerSet' <- newStdoutLoggerSet defaultBufSize
         (getter, _) <- clockDateCacher
-        return $! Logger loggerSet getter
+        return $! Logger loggerSet' getter
 
     -- | Send a message to the @Logger@ provided by @getLogger@.
     --
diff --git a/yesod-core/Yesod/Core/Content.hs b/yesod-core/Yesod/Core/Content.hs
index b6b5ffcf..a4f6b1b4 100644
--- a/yesod-core/Yesod/Core/Content.hs
+++ b/yesod-core/Yesod/Core/Content.hs
@@ -66,7 +66,11 @@ import Data.Conduit.Internal (ResumableSource (ResumableSource))
 import qualified Data.Conduit.Internal as CI
 
 import qualified Data.Aeson as J
+#if MIN_VERSION_aeson(0, 7, 0)
+import Data.Aeson.Encode (encodeToTextBuilder)
+#else
 import Data.Aeson.Encode (fromValue)
+#endif
 import qualified Blaze.ByteString.Builder.Char.Utf8 as Blaze
 import Data.Text.Lazy.Builder (toLazyText)
 import Yesod.Core.Types
@@ -243,7 +247,11 @@ instance ToContent J.Value where
     toContent = flip ContentBuilder Nothing
               . Blaze.fromLazyText
               . toLazyText
+#if MIN_VERSION_aeson(0, 7, 0)
+              . encodeToTextBuilder
+#else
               . fromValue
+#endif
 instance HasContentType J.Value where
     getContentType _ = typeJson
 
diff --git a/yesod-core/Yesod/Core/Dispatch.hs b/yesod-core/Yesod/Core/Dispatch.hs
index 9dcaf455..6a68ed36 100644
--- a/yesod-core/Yesod/Core/Dispatch.hs
+++ b/yesod-core/Yesod/Core/Dispatch.hs
@@ -42,7 +42,7 @@ import qualified Network.Wai as W
 
 import Data.ByteString.Lazy.Char8 ()
 
-import Data.Text (Text, pack)
+import Data.Text (Text)
 import Data.Monoid (mappend)
 import qualified Data.ByteString as S
 import qualified Data.ByteString.Char8 as S8
@@ -96,6 +96,7 @@ toWaiAppYre yre req =
          sendResponse $ W.responseLBS status301
                 [ ("Content-Type", "text/plain")
                 , ("Location", Blaze.ByteString.Builder.toByteString dest')
+                -- FIXME , ("Server", serverValue)
                 ] "Redirecting"
       where
         dest = joinPath y (resolveApproot y env) segments' []
@@ -152,19 +153,9 @@ toWaiAppLogger logger site = do
 warp :: YesodDispatch site => Int -> site -> IO ()
 warp port site = do
     logger <- makeLogger site
-    toWaiAppLogger logger site >>= Network.Wai.Handler.Warp.runSettings
-        Network.Wai.Handler.Warp.defaultSettings
-            { Network.Wai.Handler.Warp.settingsPort = port
-            {- FIXME
-            , Network.Wai.Handler.Warp.settingsServerName = S8.pack $ concat
-                [ "Warp/"
-                , Network.Wai.Handler.Warp.warpVersion
-                , " + Yesod/"
-                , showVersion Paths_yesod_core.version
-                , " (core)"
-                ]
-            -}
-            , Network.Wai.Handler.Warp.settingsOnException = const $ \e ->
+    toWaiAppLogger logger site >>= Network.Wai.Handler.Warp.runSettings (
+        Network.Wai.Handler.Warp.setPort port $
+        Network.Wai.Handler.Warp.setOnException (\_ e ->
                 when (shouldLog' e) $
                 messageLoggerSource
                     site
@@ -172,11 +163,20 @@ warp port site = do
                     $(qLocation >>= liftLoc)
                     "yesod-core"
                     LevelError
-                    (toLogStr $ "Exception from Warp: " ++ show e)
-            }
+                    (toLogStr $ "Exception from Warp: " ++ show e)) $
+        Network.Wai.Handler.Warp.defaultSettings)
   where
     shouldLog' = Network.Wai.Handler.Warp.defaultShouldDisplayException
 
+_serverValue :: S8.ByteString -- FIXME
+_serverValue = S8.pack $ concat
+    [ "Warp/"
+    , Network.Wai.Handler.Warp.warpVersion
+    , " + Yesod/"
+    , showVersion Paths_yesod_core.version
+    , " (core)"
+    ]
+
 -- | A default set of middlewares.
 --
 -- Since 1.2.0
diff --git a/yesod-core/Yesod/Core/Internal/Request.hs b/yesod-core/Yesod/Core/Internal/Request.hs
index cf0d9351..33683a9a 100644
--- a/yesod-core/Yesod/Core/Internal/Request.hs
+++ b/yesod-core/Yesod/Core/Internal/Request.hs
@@ -39,7 +39,6 @@ import Data.Conduit
 import Data.Conduit.List (sourceList)
 import Data.Conduit.Binary (sourceFile, sinkFile)
 import Data.Word (Word64)
-import Control.Monad.IO.Class (liftIO)
 import Control.Monad.Trans.Resource (runResourceT, ResourceT)
 import Control.Exception (throwIO)
 import Yesod.Core.Types
diff --git a/yesod-core/Yesod/Core/Internal/Response.hs b/yesod-core/Yesod/Core/Internal/Response.hs
index 83c57676..03cd816c 100644
--- a/yesod-core/Yesod/Core/Internal/Response.hs
+++ b/yesod-core/Yesod/Core/Internal/Response.hs
@@ -14,11 +14,11 @@ import           Data.CaseInsensitive         (CI)
 import qualified Data.CaseInsensitive         as CI
 import           Network.Wai
 import           Data.Conduit                 (transPipe)
-import           Control.Monad.Trans.Resource (runInternalState, getInternalState, runResourceT, InternalState, closeInternalState)
-import           Control.Monad.Trans.Class    (lift)
+import           Control.Monad.Trans.Resource (runInternalState, InternalState)
 import           Network.Wai.Internal
-import           Control.Exception            (finally)
+#if !MIN_VERSION_base(4, 6, 0)
 import           Prelude                      hiding (catch)
+#endif
 import           Web.Cookie                   (renderSetCookie)
 import           Yesod.Core.Content
 import           Yesod.Core.Types
@@ -43,7 +43,7 @@ yarToResponse :: YesodResponse
               -> IO ResponseReceived
 yarToResponse (YRWai a) _ _ _ _ sendResponse = sendResponse a
 yarToResponse (YRWaiApp app) _ _ req _ sendResponse = app req sendResponse
-yarToResponse (YRPlain s' hs ct c newSess) saveSession yreq req is sendResponse = do
+yarToResponse (YRPlain s' hs ct c newSess) saveSession yreq _req is sendResponse = do
     extraHeaders <- do
         let nsToken = maybe
                 newSess
diff --git a/yesod-core/Yesod/Core/Internal/Run.hs b/yesod-core/Yesod/Core/Internal/Run.hs
index 0c33e076..e2962619 100644
--- a/yesod-core/Yesod/Core/Internal/Run.hs
+++ b/yesod-core/Yesod/Core/Internal/Run.hs
@@ -10,7 +10,7 @@ module Yesod.Core.Internal.Run where
 import Yesod.Core.Internal.Response
 import           Blaze.ByteString.Builder     (toByteString)
 import           Control.Applicative          ((<$>))
-import           Control.Exception            (fromException, bracketOnError, evaluate)
+import           Control.Exception            (fromException, evaluate)
 import qualified Control.Exception            as E
 import           Control.Exception.Lifted     (catch)
 import           Control.Monad                (mplus)
@@ -35,7 +35,9 @@ import           Language.Haskell.TH.Syntax   (Loc, qLocation)
 import qualified Network.HTTP.Types           as H
 import           Network.Wai
 import           Network.Wai.Internal
+#if !MIN_VERSION_base(4, 6, 0)
 import           Prelude                      hiding (catch)
+#endif
 import           System.Log.FastLogger        (LogStr, toLogStr)
 import           System.Random                (newStdGen)
 import           Yesod.Core.Content
@@ -44,8 +46,7 @@ import           Yesod.Core.Types
 import           Yesod.Core.Internal.Request  (parseWaiRequest,
                                                tooLargeResponse)
 import           Yesod.Routes.Class           (Route, renderRoute)
-import Control.DeepSeq (($!!), NFData)
-import Control.Monad (liftM)
+import Control.DeepSeq (($!!))
 
 returnDeepSessionMap :: Monad m => SessionMap -> m SessionMap
 #if MIN_VERSION_bytestring(0, 10, 0)
@@ -115,6 +116,7 @@ runHandler rhe@RunHandlerEnv {..} handler yreq = withInternalState $ \resState -
                             | otherwise = status'
                      in return $ YRPlain status hs' ct c sess
                 YRWai _ -> return yar
+                YRWaiApp _ -> return yar
     let sendFile' ct fp p =
             return $ YRPlain H.status200 headers ct (ContentFile fp p) finalSession
     contents1 <- evaluate contents `E.catch` \e -> return
@@ -225,6 +227,7 @@ runFakeHandler fakeSessionMap logger site handler = liftIO $ do
           , requestBody    = return mempty
           , vault          = mempty
           , requestBodyLength = KnownLength 0
+          , requestHeaderRange = Nothing
           }
       fakeRequest =
         YesodRequest
diff --git a/yesod-core/Yesod/Core/Json.hs b/yesod-core/Yesod/Core/Json.hs
index b2669aa8..1ae81839 100644
--- a/yesod-core/Yesod/Core/Json.hs
+++ b/yesod-core/Yesod/Core/Json.hs
@@ -29,7 +29,6 @@ module Yesod.Core.Json
 
 import Yesod.Core.Handler (HandlerT, getRequest, invalidArgs, redirect, selectRep, provideRep, rawRequestBody, ProvidedRep)
 import Control.Monad.Trans.Writer (Writer)
-import Control.Monad.Trans.Resource (runExceptionT)
 import Data.Monoid (Endo)
 import Yesod.Core.Content (TypedContent)
 import Yesod.Core.Types (reqAccept)
diff --git a/yesod-core/Yesod/Core/Types.hs b/yesod-core/Yesod/Core/Types.hs
index 1a001337..4d4474b8 100644
--- a/yesod-core/Yesod/Core/Types.hs
+++ b/yesod-core/Yesod/Core/Types.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE DeriveDataTypeable         #-}
 {-# LANGUAGE TupleSections #-}
 {-# LANGUAGE FlexibleInstances          #-}
@@ -54,7 +55,9 @@ import           Yesod.Core.Internal.Util           (getTime, putTime)
 import           Control.Monad.Trans.Class          (MonadTrans (..))
 import           Yesod.Routes.Class                 (RenderRoute (..), ParseRoute (..))
 import           Control.Monad.Reader               (MonadReader (..))
+#if !MIN_VERSION_base(4, 6, 0)
 import Prelude hiding (catch)
+#endif
 import Control.DeepSeq (NFData (rnf))
 import Data.Conduit.Lazy (MonadActive, monadActive)
 import Yesod.Core.TypeCache (TypeMap, KeyedTypeMap)
diff --git a/yesod-core/Yesod/Routes/Overlap.hs b/yesod-core/Yesod/Routes/Overlap.hs
index 52ab9c97..bccb685a 100644
--- a/yesod-core/Yesod/Routes/Overlap.hs
+++ b/yesod-core/Yesod/Routes/Overlap.hs
@@ -37,8 +37,8 @@ data Overlap t = Overlap
     }
 
 data OverlapF = OverlapF
-    { overlapF1 :: [String]
-    , overlapF2 :: [String]
+    { _overlapF1 :: [String]
+    , _overlapF2 :: [String]
     }
 
 overlaps :: [Piece t] -> [Piece t] -> Bool -> Bool -> Bool
diff --git a/yesod-core/Yesod/Routes/TH/Dispatch.hs b/yesod-core/Yesod/Routes/TH/Dispatch.hs
index 7914febe..f073443f 100644
--- a/yesod-core/Yesod/Routes/TH/Dispatch.hs
+++ b/yesod-core/Yesod/Routes/TH/Dispatch.hs
@@ -118,8 +118,8 @@ mkDispatchClause MkDispatchSettings {..} resources = do
             []
       where
         handleDispatch :: Dispatch a -> [Exp] -> Q (Exp, Pat)
-        handleDispatch dispatch dyns =
-            case dispatch of
+        handleDispatch dispatch' dyns =
+            case dispatch' of
                 Methods multi methods -> do
                     (finalPat, mfinalE) <-
                         case multi of
diff --git a/yesod-core/yesod-core.cabal b/yesod-core/yesod-core.cabal
index 6b995de4..9423fea8 100644
--- a/yesod-core/yesod-core.cabal
+++ b/yesod-core/yesod-core.cabal
@@ -50,7 +50,7 @@ library
                    , directory             >= 1
                    , vector                >= 0.9      && < 0.11
                    , aeson                 >= 0.5
-                   , fast-logger           >= 2.1
+                   , fast-logger           >= 2.2
                    , wai-logger            >= 0.2
                    , monad-logger          >= 0.3.1    && < 0.4
                    , conduit               >= 1.2