diff --git a/yesod-core/Yesod/Core.hs b/yesod-core/Yesod/Core.hs
index a63eba8b..4901a115 100644
--- a/yesod-core/Yesod/Core.hs
+++ b/yesod-core/Yesod/Core.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE TemplateHaskell #-}
 {-# LANGUAGE UndecidableInstances #-}
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE FlexibleContexts #-}
@@ -134,11 +133,10 @@ import Text.Blaze.Html (Html, toHtml, preEscapedToMarkup)
 import Control.Monad.Logger
 import Control.Monad.Trans.Class (MonadTrans (..))
 import Yesod.Core.Internal.Session
-import Yesod.Core.Internal.Run (yesodRunner)
+import Yesod.Core.Internal.Run (yesodRunner, yesodRender)
 import Yesod.Core.Class.Yesod
 import Yesod.Core.Class.Dispatch
 import Yesod.Core.Class.Breadcrumbs
-import Yesod.Core.Internal.Run (yesodRender)
 import qualified Yesod.Core.Internal.Run
 import qualified Paths_yesod_core
 import Data.Version (showVersion)
diff --git a/yesod-core/Yesod/Core/Class/Dispatch.hs b/yesod-core/Yesod/Core/Class/Dispatch.hs
index cf998477..7f52b9fb 100644
--- a/yesod-core/Yesod/Core/Class/Dispatch.hs
+++ b/yesod-core/Yesod/Core/Class/Dispatch.hs
@@ -1,7 +1,6 @@
 {-# LANGUAGE MultiParamTypeClasses #-}
 {-# LANGUAGE RecordWildCards #-}
 {-# LANGUAGE RankNTypes #-}
-{-# LANGUAGE ViewPatterns #-}
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE TypeFamilies #-}
 {-# LANGUAGE FlexibleContexts  #-}
@@ -25,10 +24,9 @@ class YesodSubDispatch sub m where
                      -> W.Application
 
 instance YesodSubDispatch WaiSubsite master where
-    yesodSubDispatch YesodSubRunnerEnv {..} req =
-        app req
+    yesodSubDispatch YesodSubRunnerEnv {..} = app
       where
-        WaiSubsite app = ysreGetSub $ yreSite $ ysreParentEnv
+        WaiSubsite app = ysreGetSub $ yreSite ysreParentEnv
 
 -- | A helper function for creating YesodSubDispatch instances, used by the
 -- internal generated code. This function has been exported since 1.4.11.
diff --git a/yesod-core/Yesod/Core/Class/Yesod.hs b/yesod-core/Yesod/Core/Class/Yesod.hs
index 3161aee6..5893e1af 100644
--- a/yesod-core/Yesod/Core/Class/Yesod.hs
+++ b/yesod-core/Yesod/Core/Class/Yesod.hs
@@ -5,7 +5,6 @@
 {-# LANGUAGE CPP               #-}
 module Yesod.Core.Class.Yesod where
 
-import           Control.Monad.Logger               (logErrorS)
 import           Yesod.Core.Content
 import           Yesod.Core.Handler
 
@@ -15,16 +14,18 @@ import           Blaze.ByteString.Builder           (Builder)
 import           Blaze.ByteString.Builder.Char.Utf8 (fromText)
 import           Control.Arrow                      ((***), second)
 import           Control.Exception                  (bracket)
+#if __GLASGOW_HASKELL__ < 710
+import           Control.Applicative                ((<$>))
+#endif
 import           Control.Monad                      (forM, when, void)
 import           Control.Monad.IO.Class             (MonadIO (liftIO))
 import           Control.Monad.Logger               (LogLevel (LevelInfo, LevelOther),
-                                                     LogSource)
+                                                     LogSource, logErrorS)
 import           Control.Monad.Trans.Resource       (InternalState, createInternalState, closeInternalState)
 import qualified Data.ByteString.Char8              as S8
 import qualified Data.ByteString.Lazy               as L
 import Data.Aeson (object, (.=))
-import           Data.List                          (foldl')
-import           Data.List                          (nub)
+import           Data.List                          (foldl', nub)
 import qualified Data.Map                           as Map
 import           Data.Monoid
 import           Data.Text                          (Text)
@@ -43,14 +44,13 @@ import           Network.Wai.Parse                  (lbsBackEnd,
 import           Network.Wai.Logger                 (ZonedDate, clockDateCacher)
 import           System.Log.FastLogger
 import           Text.Blaze                         (customAttribute, textTag,
-                                                     toValue, (!))
-import           Text.Blaze                         (preEscapedToMarkup)
+                                                     toValue, (!),
+                                                     preEscapedToMarkup)
 import qualified Text.Blaze.Html5                   as TBH
 import           Text.Hamlet
 import           Text.Julius
 import qualified Web.ClientSession                  as CS
-import           Web.Cookie                         (parseCookies)
-import           Web.Cookie                         (SetCookie (..))
+import           Web.Cookie                         (SetCookie (..), parseCookies)
 import           Yesod.Core.Types
 import           Yesod.Core.Internal.Session
 import           Yesod.Core.Widget
@@ -237,7 +237,7 @@ class RenderRoute site => Yesod site where
     --
     -- Default: Uses clientsession with a 2 hour timeout.
     makeSessionBackend :: site -> IO (Maybe SessionBackend)
-    makeSessionBackend _ = fmap Just $ defaultClientSessionBackend 120 CS.defaultKeyFile
+    makeSessionBackend _ = Just <$> defaultClientSessionBackend 120 CS.defaultKeyFile
 
     -- | How to store uploaded files.
     --
@@ -388,8 +388,7 @@ sslOnlyMiddleware timeout handler = do
 --
 -- Since 1.2.0
 authorizationCheck :: Yesod site => HandlerT site IO ()
-authorizationCheck = do
-    getCurrentRoute >>= maybe (return ()) checkUrl
+authorizationCheck = getCurrentRoute >>= maybe (return ()) checkUrl
   where
     checkUrl url = do
         isWrite <- isWriteRequest url
@@ -399,21 +398,21 @@ authorizationCheck = do
             AuthenticationRequired -> do
                 master <- getYesod
                 case authRoute master of
-                    Nothing -> void $ notAuthenticated
-                    Just url' -> do
+                    Nothing -> void notAuthenticated
+                    Just url' ->
                       void $ selectRep $ do
                           provideRepType typeHtml $ do
                               setUltDestCurrent
                               void $ redirect url'
                           provideRepType typeJson $
-                              void $ notAuthenticated
+                              void notAuthenticated
             Unauthorized s' -> permissionDenied s'
 
 -- | Calls 'csrfCheckMiddleware' with 'isWriteRequest', 'defaultCsrfHeaderName', and 'defaultCsrfParamName' as parameters.
 --
 -- Since 1.4.14
 defaultCsrfCheckMiddleware :: Yesod site => HandlerT site IO res -> HandlerT site IO res
-defaultCsrfCheckMiddleware handler = do
+defaultCsrfCheckMiddleware handler =
     csrfCheckMiddleware
         handler
         (getCurrentRoute >>= maybe (return False) isWriteRequest)
@@ -592,12 +591,9 @@ defaultErrorHandler NotAuthenticated = selectRep $ do
         -- The client will just use the authentication_url in the JSON
         site <- getYesod
         rend <- getUrlRender
-        return $ object $ [
-          "message" .= ("Not logged in"::Text)
-          ] ++
-          case authRoute site of
-              Nothing -> []
-              Just url -> ["authentication_url" .= rend url]
+        let apair u = ["authentication_url" .= rend u]
+            content = maybe [] apair (authRoute site)
+        return $ object $ ("message" .= ("Not logged in"::Text)):content
 
 defaultErrorHandler (PermissionDenied msg) = selectRep $ do
     provideRep $ defaultLayout $ do
@@ -607,9 +603,7 @@ defaultErrorHandler (PermissionDenied msg) = selectRep $ do
             <p>#{msg}
         |]
     provideRep $
-        return $ object $ [
-          "message" .= ("Permission Denied. " <> msg)
-          ]
+        return $ object ["message" .= ("Permission Denied. " <> msg)]
 
 defaultErrorHandler (InvalidArgs ia) = selectRep $ do
     provideRep $ defaultLayout $ do
@@ -641,8 +635,8 @@ defaultErrorHandler (BadMethod m) = selectRep $ do
     provideRep $ return $ object ["message" .= ("Bad method" :: Text), "method" .= TE.decodeUtf8With TEE.lenientDecode m]
 
 asyncHelper :: (url -> [x] -> Text)
-         -> [Script (url)]
-         -> Maybe (JavascriptUrl (url))
+         -> [Script url]
+         -> Maybe (JavascriptUrl url)
          -> Maybe Text
          -> (Maybe (HtmlUrl url), [Text])
 asyncHelper render scripts jscript jsLoc =
@@ -732,8 +726,7 @@ defaultClientSessionBackend :: Int -- ^ minutes
                             -> IO SessionBackend
 defaultClientSessionBackend minutes fp = do
   key <- CS.getKey fp
-  let timeout = fromIntegral (minutes * 60)
-  (getCachedDate, _closeDateCacher) <- clientSessionDateCacher timeout
+  (getCachedDate, _closeDateCacher) <- clientSessionDateCacher (minToSec minutes)
   return $ clientSessionBackend key getCachedDate
 
 -- | Create a @SessionBackend@ which reads the session key from the named
@@ -759,10 +752,12 @@ envClientSessionBackend :: Int -- ^ minutes
                         -> IO SessionBackend
 envClientSessionBackend minutes name = do
     key <- CS.getKeyEnv name
-    let timeout = fromIntegral (minutes * 60)
-    (getCachedDate, _closeDateCacher) <- clientSessionDateCacher timeout
+    (getCachedDate, _closeDateCacher) <- clientSessionDateCacher $ minToSec minutes
     return $ clientSessionBackend key getCachedDate
 
+minToSec :: (Integral a, Num b) => a -> b
+minToSec minutes = fromIntegral (minutes * 60)
+
 jsToHtml :: Javascript -> Html
 jsToHtml (Javascript b) = preEscapedToMarkup $ toLazyText b
 
@@ -818,8 +813,14 @@ loadClientSession key getCachedDate sessionName req = load
 -- turn the TH Loc loaction information into a human readable string
 -- leaving out the loc_end parameter
 fileLocationToString :: Loc -> String
-fileLocationToString loc = (loc_package loc) ++ ':' : (loc_module loc) ++
-  ' ' : (loc_filename loc) ++ ':' : (line loc) ++ ':' : (char loc)
+fileLocationToString loc =
+    concat
+      [ loc_package loc
+      , ':' : loc_module loc
+      , ' ' : loc_filename loc
+      , ':' : line loc
+      , ':' : char loc
+      ]
   where
     line = show . fst . loc_start
     char = show . snd . loc_start
diff --git a/yesod-core/Yesod/Core/Content.hs b/yesod-core/Yesod/Core/Content.hs
index 2e850362..faab94ce 100644
--- a/yesod-core/Yesod/Core/Content.hs
+++ b/yesod-core/Yesod/Core/Content.hs
@@ -53,8 +53,6 @@ import qualified Data.ByteString as B
 import qualified Data.ByteString.Lazy as L
 import Data.Text.Lazy (Text, pack)
 import qualified Data.Text as T
-import Control.Monad (liftM)
-
 import Blaze.ByteString.Builder (Builder, fromByteString, fromLazyByteString)
 #if __GLASGOW_HASKELL__ < 710
 import Data.Monoid (mempty)
@@ -62,6 +60,7 @@ import Data.Monoid (mempty)
 import Text.Hamlet (Html)
 import Text.Blaze.Html.Renderer.Utf8 (renderHtmlBuilder)
 import Data.Conduit (Source, Flush (Chunk), ResumableSource, mapOutput)
+import Control.Monad (liftM)
 import Control.Monad.Trans.Resource (ResourceT)
 import Data.Conduit.Internal (ResumableSource (ResumableSource))
 import qualified Data.Conduit.Internal as CI
diff --git a/yesod-core/Yesod/Core/Dispatch.hs b/yesod-core/Yesod/Core/Dispatch.hs
index 7911877d..c220ecec 100644
--- a/yesod-core/Yesod/Core/Dispatch.hs
+++ b/yesod-core/Yesod/Core/Dispatch.hs
@@ -85,7 +85,7 @@ toWaiAppPlain site = do
     sb <- makeSessionBackend site
     gen <- MWC.createSystemRandom
     getMaxExpires <- getGetMaxExpires
-    return $ toWaiAppYre $ YesodRunnerEnv
+    return $ toWaiAppYre YesodRunnerEnv
             { yreLogger = logger
             , yreSite = site
             , yreSessionBackend = sb
@@ -119,8 +119,8 @@ toWaiAppYre yre req =
         dest' =
             if S.null (W.rawQueryString env)
                 then dest
-                else (dest `mappend`
-                     Blaze.ByteString.Builder.fromByteString (W.rawQueryString env))
+                else dest `mappend`
+                     Blaze.ByteString.Builder.fromByteString (W.rawQueryString env)
 
 -- | Same as 'toWaiAppPlain', but provides a default set of middlewares. This
 -- set may change with future releases, but currently covers:
@@ -184,7 +184,7 @@ 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
@@ -231,7 +231,7 @@ warpEnv :: YesodDispatch site => site -> IO ()
 warpEnv site = do
     env <- getEnvironment
     case lookup "PORT" env of
-        Nothing -> error $ "warpEnv: no PORT environment variable found"
+        Nothing -> error "warpEnv: no PORT environment variable found"
         Just portS ->
             case readMay portS of
                 Nothing -> error $ "warpEnv: invalid PORT environment variable: " ++ show portS
diff --git a/yesod-core/Yesod/Core/Handler.hs b/yesod-core/Yesod/Core/Handler.hs
index a0230e18..29948be0 100644
--- a/yesod-core/Yesod/Core/Handler.hs
+++ b/yesod-core/Yesod/Core/Handler.hs
@@ -189,10 +189,10 @@ import           Control.Applicative           ((<$>))
 import           Data.Monoid                   (mempty, mappend)
 #endif
 import           Control.Applicative           ((<|>))
-import           Control.Exception             (evaluate, SomeException)
+import           Control.Exception             (evaluate, SomeException, throwIO)
 import           Control.Exception.Lifted      (handle)
 
-import           Control.Monad                 (liftM, void)
+import           Control.Monad                 (void, liftM, unless)
 import qualified Control.Monad.Trans.Writer    as Writer
 
 import           Control.Monad.IO.Class        (MonadIO, liftIO)
@@ -235,24 +235,19 @@ import           Web.PathPieces                (PathPiece(..))
 import           Yesod.Core.Class.Handler
 import           Yesod.Core.Types
 import           Yesod.Routes.Class            (Route)
-import Control.Exception (throwIO)
-import Blaze.ByteString.Builder (Builder)
-import Safe (headMay)
-import Data.CaseInsensitive (CI)
+import           Blaze.ByteString.Builder (Builder)
+import           Safe (headMay)
+import           Data.CaseInsensitive (CI)
 import qualified Data.Conduit.List as CL
-import Control.Monad (unless)
-import           Control.Monad.Trans.Resource  (MonadResource, InternalState, runResourceT, withInternalState, getInternalState, liftResourceT, resourceForkIO
-              )
+import           Control.Monad.Trans.Resource  (MonadResource, InternalState, runResourceT, withInternalState, getInternalState, liftResourceT, resourceForkIO)
 import qualified System.PosixCompat.Files as PC
-import Control.Monad.Trans.Control (control, MonadBaseControl)
-import Data.Conduit (Source, transPipe, Flush (Flush), yield, Producer
-                    , Sink
-                   )
+import           Control.Monad.Trans.Control (control, MonadBaseControl)
+import           Data.Conduit (Source, transPipe, Flush (Flush), yield, Producer, Sink)
 import qualified Yesod.Core.TypeCache as Cache
 import qualified Data.Word8 as W8
 import qualified Data.Foldable as Fold
-import Data.Default
-import Control.Monad.Logger (MonadLogger, logWarnS)
+import           Data.Default
+import           Control.Monad.Logger (MonadLogger, logWarnS)
 
 get :: MonadHandler m => m GHState
 get = liftHandlerT $ HandlerT $ I.readIORef . handlerState
@@ -305,7 +300,7 @@ rbHelper' :: NWP.BackEnd x
           -> W.Request
           -> IO ([(Text, Text)], [(Text, FileInfo)])
 rbHelper' backend mkFI req =
-    (map fix1 *** mapMaybe fix2) <$> (NWP.parseRequestBody backend req)
+    (map fix1 *** mapMaybe fix2) <$> NWP.parseRequestBody backend req
   where
     fix1 = go *** go
     fix2 (x, NWP.FileInfo a' b c)
@@ -324,29 +319,29 @@ askHandlerEnv = liftHandlerT $ HandlerT $ return . handlerEnv
 
 -- | Get the master site application argument.
 getYesod :: MonadHandler m => m (HandlerSite m)
-getYesod = rheSite `liftM` askHandlerEnv
+getYesod = rheSite <$> askHandlerEnv
 
 -- | Get a specific component of the master site application argument.
 --   Analogous to the 'gets' function for operating on 'StateT'.
 getsYesod :: MonadHandler m => (HandlerSite m -> a) -> m a
-getsYesod f = (f . rheSite) `liftM` askHandlerEnv
+getsYesod f = (f . rheSite) <$> askHandlerEnv
 
 -- | Get the URL rendering function.
 getUrlRender :: MonadHandler m => m (Route (HandlerSite m) -> Text)
 getUrlRender = do
-    x <- rheRender `liftM` askHandlerEnv
+    x <- rheRender <$> askHandlerEnv
     return $ flip x []
 
 -- | The URL rendering function with query-string parameters.
 getUrlRenderParams
     :: MonadHandler m
     => m (Route (HandlerSite m) -> [(Text, Text)] -> Text)
-getUrlRenderParams = rheRender `liftM` askHandlerEnv
+getUrlRenderParams = rheRender <$> askHandlerEnv
 
 -- | Get the route requested by the user. If this is a 404 response- where the
 -- user requested an invalid route- this function will return 'Nothing'.
 getCurrentRoute :: MonadHandler m => m (Maybe (Route (HandlerSite m)))
-getCurrentRoute = rheRoute `liftM` askHandlerEnv
+getCurrentRoute = rheRoute <$> askHandlerEnv
 
 -- | Returns a function that runs 'HandlerT' actions inside @IO@.
 --
@@ -487,7 +482,7 @@ setUltDestCurrent = do
     case route of
         Nothing -> return ()
         Just r -> do
-            gets' <- reqGetParams `liftM` getRequest
+            gets' <- reqGetParams <$> getRequest
             setUltDest (r, gets')
 
 -- | Sets the ultimate destination to the referer request header, if present.
@@ -541,7 +536,7 @@ addMessage status msg = do
     addMsg = maybe msg' (S.append msg' . S.cons W8._nul)
     msg' = S.append
         (encodeUtf8 status)
-        (W8._nul `S.cons` (L.toStrict $ renderHtml msg))
+        (W8._nul `S.cons` L.toStrict (renderHtml msg))
 
 -- | Adds a message in the user's session but uses RenderMessage to allow for i18n
 --
@@ -568,7 +563,7 @@ getMessages = do
   where
     enlist = pairup . S.split W8._nul
     pairup [] = []
-    pairup [x] = []
+    pairup [_] = []
     pairup (s:v:xs) = (decode s, preEscapedToHtml (decode v)) : pairup xs
     decode = decodeUtf8With lenientDecode
 
@@ -584,7 +579,7 @@ setMessageI = addMessageI ""
 -- | Gets just the last message in the user's session,
 -- discards the rest and the status
 getMessage :: MonadHandler m => m (Maybe Html)
-getMessage = (return . fmap snd . headMay) =<< getMessages
+getMessage = fmap (fmap snd . headMay) getMessages
 
 -- | Bypass remaining handler code and output the given file.
 --
@@ -657,7 +652,7 @@ sendRawResponseNoConduit
     -> m a
 sendRawResponseNoConduit raw = control $ \runInIO ->
     liftIO $ throwIO $ HCWai $ flip W.responseRaw fallback
-    $ \src sink -> runInIO (raw src sink) >> return ()
+    $ \src sink -> void $ runInIO (raw src sink)
   where
     fallback = W.responseLBS H.status500 [("Content-Type", "text/plain")]
         "sendRawResponse: backend does not support raw responses"
@@ -672,7 +667,7 @@ sendRawResponse :: (MonadHandler m, MonadBaseControl IO m)
                 -> m a
 sendRawResponse raw = control $ \runInIO ->
     liftIO $ throwIO $ HCWai $ flip W.responseRaw fallback
-    $ \src sink -> runInIO (raw (src' src) (CL.mapM_ sink)) >> return ()
+    $ \src sink -> void $ runInIO $ raw (src' src) (CL.mapM_ sink)
   where
     fallback = W.responseLBS H.status500 [("Content-Type", "text/plain")]
         "sendRawResponse: backend does not support raw responses"
@@ -901,17 +896,17 @@ instance (RedirectUrl master a, PathPiece b) => RedirectUrl master (Fragment a b
 
 -- | Lookup for session data.
 lookupSession :: MonadHandler m => Text -> m (Maybe Text)
-lookupSession = (liftM . fmap) (decodeUtf8With lenientDecode) . lookupSessionBS
+lookupSession = (fmap . fmap) (decodeUtf8With lenientDecode) . lookupSessionBS
 
 -- | Lookup for session data in binary format.
 lookupSessionBS :: MonadHandler m => Text -> m (Maybe S.ByteString)
 lookupSessionBS n = do
-    m <- liftM ghsSession get
+    m <- fmap ghsSession get
     return $ Map.lookup n m
 
 -- | Get all session variables.
 getSession :: MonadHandler m => m SessionMap
-getSession = liftM ghsSession get
+getSession = fmap ghsSession get
 
 -- | Get a unique identifier.
 newIdent :: MonadHandler m => m Text
@@ -976,13 +971,13 @@ withUrlRenderer f = do
 
 -- | Get the request\'s 'W.Request' value.
 waiRequest :: MonadHandler m => m W.Request
-waiRequest = reqWaiRequest `liftM` getRequest
+waiRequest = reqWaiRequest <$> getRequest
 
 getMessageRender :: (MonadHandler m, RenderMessage (HandlerSite m) message)
                  => m (message -> Text)
 getMessageRender = do
     env <- askHandlerEnv
-    l <- reqLangs `liftM` getRequest
+    l <- reqLangs <$> getRequest
     return $ renderMessage (rheSite env) l
 
 -- | Use a per-request cache to avoid performing the same action multiple times.
@@ -1045,7 +1040,7 @@ cachedBy k action = do
 --
 -- This is handled by parseWaiRequest (not exposed).
 languages :: MonadHandler m => m [Text]
-languages = reqLangs `liftM` getRequest
+languages = reqLangs <$> getRequest
 
 lookup' :: Eq a => a -> [(a, b)] -> [b]
 lookup' a = map snd . filter (\x -> a == fst x)
@@ -1054,7 +1049,7 @@ lookup' a = map snd . filter (\x -> a == fst x)
 --
 -- Since 1.2.2
 lookupHeader :: MonadHandler m => CI S8.ByteString -> m (Maybe S8.ByteString)
-lookupHeader = liftM listToMaybe . lookupHeaders
+lookupHeader = fmap listToMaybe . lookupHeaders
 
 -- | Lookup a request header.
 --
@@ -1069,11 +1064,9 @@ lookupHeaders key = do
 --
 -- Since 1.4.9
 lookupBasicAuth :: (MonadHandler m) => m (Maybe (Text, Text))
-lookupBasicAuth = fmap (>>= getBA)
-                  (lookupHeader "Authorization")
+lookupBasicAuth = fmap (>>= getBA) (lookupHeader "Authorization")
   where
-    getBA bs = (\(x, y) -> ( decodeUtf8With lenientDecode x
-                          , decodeUtf8With lenientDecode y))
+    getBA bs = (decodeUtf8With lenientDecode *** decodeUtf8With lenientDecode)
                <$> extractBasicAuth bs
 
 -- | Lookup bearer authentication datafrom __Authorization__ header of
@@ -1096,7 +1089,7 @@ lookupGetParams pn = do
 
 -- | Lookup for GET parameters.
 lookupGetParam :: MonadHandler m => Text -> m (Maybe Text)
-lookupGetParam = liftM listToMaybe . lookupGetParams
+lookupGetParam = fmap listToMaybe . lookupGetParams
 
 -- | Lookup for POST parameters.
 lookupPostParams :: (MonadResource m, MonadHandler m) => Text -> m [Text]
@@ -1107,13 +1100,13 @@ lookupPostParams pn = do
 lookupPostParam :: (MonadResource m, MonadHandler m)
                 => Text
                 -> m (Maybe Text)
-lookupPostParam = liftM listToMaybe . lookupPostParams
+lookupPostParam = fmap listToMaybe . lookupPostParams
 
 -- | Lookup for POSTed files.
 lookupFile :: (MonadHandler m, MonadResource m)
            => Text
            -> m (Maybe FileInfo)
-lookupFile = liftM listToMaybe . lookupFiles
+lookupFile = fmap listToMaybe . lookupFiles
 
 -- | Lookup for POSTed files.
 lookupFiles :: (MonadHandler m, MonadResource m)
@@ -1125,7 +1118,7 @@ lookupFiles pn = do
 
 -- | Lookup for cookie data.
 lookupCookie :: MonadHandler m => Text -> m (Maybe Text)
-lookupCookie = liftM listToMaybe . lookupCookies
+lookupCookie = fmap listToMaybe . lookupCookies
 
 -- | Lookup for cookie data.
 lookupCookies :: MonadHandler m => Text -> m [Text]
@@ -1160,7 +1153,7 @@ selectRep :: MonadHandler m
 selectRep w = do
     -- the content types are already sorted by q values
     -- which have been stripped
-    cts <- liftM reqAccept getRequest
+    cts <- fmap reqAccept getRequest
 
     case mapMaybe tryAccept cts of
         [] ->
@@ -1175,8 +1168,7 @@ selectRep w = do
     explainUnaccepted :: Text
     explainUnaccepted = "no match found for accept header"
 
-    returnRep (ProvidedRep ct mcontent) =
-        mcontent >>= return . TypedContent ct
+    returnRep (ProvidedRep ct mcontent) = fmap (TypedContent ct) mcontent
 
     reps = appEndo (Writer.execWriter w) []
 
@@ -1235,7 +1227,7 @@ provideRepType :: (Monad m, ToContent a)
                -> m a
                -> Writer.Writer (Endo [ProvidedRep m]) ()
 provideRepType ct handler =
-    Writer.tell $ Endo $ (ProvidedRep ct (liftM toContent handler):)
+    Writer.tell $ Endo (ProvidedRep ct (liftM toContent handler):)
 
 -- | Stream in the raw request body without any parsing.
 --
diff --git a/yesod-core/Yesod/Core/Internal/Request.hs b/yesod-core/Yesod/Core/Internal/Request.hs
index 7f5a6afc..b7e4e3ca 100644
--- a/yesod-core/Yesod/Core/Internal/Request.hs
+++ b/yesod-core/Yesod/Core/Internal/Request.hs
@@ -1,5 +1,4 @@
-{-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE CPP #-}
+{-# LANGUAGE OverloadedStrings, CPP #-}
 module Yesod.Core.Internal.Request
     ( parseWaiRequest
     , RequestBodyContents
@@ -37,7 +36,7 @@ import Data.Text.Encoding.Error (lenientDecode)
 import Data.Conduit
 import Data.Conduit.List (sourceList)
 import Data.Conduit.Binary (sourceFile, sinkFile)
-import Data.Word (Word64)
+import Data.Word (Word8, Word64)
 import Control.Monad.Trans.Resource (runResourceT, ResourceT)
 import Control.Exception (throwIO)
 import Control.Monad ((<=<), liftM)
@@ -47,7 +46,6 @@ import Data.IORef
 import qualified System.Random.MWC as MWC
 import Control.Monad.Primitive (PrimMonad, PrimState)
 import qualified Data.Vector.Storable as V
-import Data.Word (Word8)
 import Data.ByteString.Internal (ByteString (PS))
 import qualified Data.Word8 as Word8
 
@@ -78,7 +76,7 @@ parseWaiRequest :: W.Request
                 -> SessionMap
                 -> Bool
                 -> Maybe Word64 -- ^ max body size
-                -> (Either (IO YesodRequest) (MWC.GenIO -> IO YesodRequest))
+                -> Either (IO YesodRequest) (MWC.GenIO -> IO YesodRequest)
 parseWaiRequest env session useToken mmaxBodySize =
     -- In most cases, we won't need to generate any random values. Therefore,
     -- we split our results: if we need a random generator, return a Right
@@ -147,7 +145,7 @@ httpAccept = NWP.parseHttpAccept
 
 addTwoLetters :: ([Text] -> [Text], Set.Set Text) -> [Text] -> [Text]
 addTwoLetters (toAdd, exist) [] =
-    filter (flip Set.notMember exist) $ toAdd []
+    filter (`Set.notMember` exist) $ toAdd []
 addTwoLetters (toAdd, exist) (l:ls) =
     l : addTwoLetters (toAdd', exist') ls
   where
@@ -177,7 +175,8 @@ fromByteVector v =
 {-# INLINE fromByteVector #-}
 
 mkFileInfoLBS :: Text -> Text -> L.ByteString -> FileInfo
-mkFileInfoLBS name ct lbs = FileInfo name ct (sourceList $ L.toChunks lbs) (\fp -> L.writeFile fp lbs)
+mkFileInfoLBS name ct lbs =
+    FileInfo name ct (sourceList $ L.toChunks lbs) (`L.writeFile` lbs)
 
 mkFileInfoFile :: Text -> Text -> FilePath -> FileInfo
 mkFileInfoFile name ct fp = FileInfo name ct (sourceFile fp) (\dst -> runResourceT $ sourceFile fp $$ sinkFile dst)
diff --git a/yesod-core/Yesod/Core/Internal/Response.hs b/yesod-core/Yesod/Core/Internal/Response.hs
index 03cd816c..7b2f2dde 100644
--- a/yesod-core/Yesod/Core/Internal/Response.hs
+++ b/yesod-core/Yesod/Core/Internal/Response.hs
@@ -1,19 +1,15 @@
 {-# LANGUAGE CPP               #-}
 {-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE PatternGuards     #-}
 {-# LANGUAGE RankNTypes        #-}
-{-# LANGUAGE RecordWildCards   #-}
-{-# LANGUAGE TemplateHaskell   #-}
 module Yesod.Core.Internal.Response where
 
-import           Blaze.ByteString.Builder     (toByteString)
 import           Data.ByteString              (ByteString)
 import qualified Data.ByteString              as S
 import qualified Data.ByteString.Char8        as S8
 import           Data.CaseInsensitive         (CI)
 import qualified Data.CaseInsensitive         as CI
 import           Network.Wai
-import           Data.Conduit                 (transPipe)
+import           Control.Monad                (mplus)
 import           Control.Monad.Trans.Resource (runInternalState, InternalState)
 import           Network.Wai.Internal
 #if !MIN_VERSION_base(4, 6, 0)
@@ -26,12 +22,12 @@ import qualified Network.HTTP.Types           as H
 import qualified Data.Text                    as T
 import           Control.Exception            (SomeException, handle)
 import           Blaze.ByteString.Builder     (fromLazyByteString,
-                                               toLazyByteString)
+                                               toLazyByteString, toByteString)
 import qualified Data.ByteString.Lazy         as L
 import qualified Data.Map                     as Map
 import           Yesod.Core.Internal.Request  (tokenKey)
 import           Data.Text.Encoding           (encodeUtf8)
-import           Data.Conduit                 (Flush (..), ($$))
+import           Data.Conduit                 (Flush (..), ($$), transPipe)
 import qualified Data.Conduit.List            as CL
 
 yarToResponse :: YesodResponse
@@ -58,11 +54,10 @@ yarToResponse (YRPlain s' hs ct c newSess) saveSession yreq _req is sendResponse
     let go (ContentBuilder b mlen) = do
             let hs' = maybe finalHeaders finalHeaders' mlen
             sendResponse $ ResponseBuilder s hs' b
-        go (ContentFile fp p) = do
-            sendResponse $ ResponseFile s finalHeaders fp p
+        go (ContentFile fp p) = sendResponse $ ResponseFile s finalHeaders fp p
         go (ContentSource body) = sendResponse $ responseStream s finalHeaders
-            $ \sendChunk flush -> do
-                transPipe (flip runInternalState is) body
+            $ \sendChunk flush ->
+                transPipe (`runInternalState` is) body
                 $$ CL.mapM_ (\mchunk ->
                     case mchunk of
                         Flush -> flush
@@ -91,7 +86,7 @@ defaultStatus = H.mkStatus (-1) "INVALID DEFAULT STATUS"
 headerToPair :: Header
              -> (CI ByteString, ByteString)
 headerToPair (AddCookie sc) =
-    ("Set-Cookie", toByteString $ renderSetCookie $ sc)
+    ("Set-Cookie", toByteString $ renderSetCookie sc)
 headerToPair (DeleteCookie key path) =
     ( "Set-Cookie"
     , S.concat
@@ -107,7 +102,7 @@ evaluateContent :: Content -> IO (Either ErrorResponse Content)
 evaluateContent (ContentBuilder b mlen) = handle f $ do
     let lbs = toLazyByteString b
         len = L.length lbs
-        mlen' = maybe (Just $ fromIntegral len) Just mlen
+        mlen' = mlen `mplus` Just (fromIntegral len)
     len `seq` return (Right $ ContentBuilder (fromLazyByteString lbs) mlen')
   where
     f :: SomeException -> IO (Either ErrorResponse Content)
diff --git a/yesod-core/Yesod/Core/Internal/Run.hs b/yesod-core/Yesod/Core/Internal/Run.hs
index 9bd1e9c0..b8ed115d 100644
--- a/yesod-core/Yesod/Core/Internal/Run.hs
+++ b/yesod-core/Yesod/Core/Internal/Run.hs
@@ -11,6 +11,7 @@ module Yesod.Core.Internal.Run where
 
 #if __GLASGOW_HASKELL__ < 710
 import           Data.Monoid                  (Monoid, mempty)
+import           Control.Applicative          ((<$>))
 #endif
 import Yesod.Core.Internal.Response
 import           Blaze.ByteString.Builder     (toByteString)
@@ -102,7 +103,7 @@ basicRunHandler rhe handler yreq resState = do
         (\e ->
             case fromException e of
                 Just e' -> return e'
-                Nothing -> fmap HCError $ toErrorHandler e)
+                Nothing -> HCError <$> toErrorHandler e)
 
     -- Get the raw state and return
     state <- I.readIORef istate
@@ -330,7 +331,7 @@ yesodRunner handler' YesodRunnerEnv {..} route req sendResponse
   | otherwise = do
     let dontSaveSession _ = return []
     (session, saveSession) <- liftIO $
-        maybe (return (Map.empty, dontSaveSession)) (\sb -> sbLoadSession sb req) yreSessionBackend
+        maybe (return (Map.empty, dontSaveSession)) (`sbLoadSession` req) yreSessionBackend
     maxExpires <- yreGetMaxExpires
     let mkYesodReq = parseWaiRequest req session (isJust yreSessionBackend) mmaxLen
     let yreq =
diff --git a/yesod-core/Yesod/Core/Internal/Session.hs b/yesod-core/Yesod/Core/Internal/Session.hs
index f8bc5f4d..e83089ff 100644
--- a/yesod-core/Yesod/Core/Internal/Session.hs
+++ b/yesod-core/Yesod/Core/Internal/Session.hs
@@ -11,11 +11,9 @@ import qualified Web.ClientSession as CS
 import Data.Serialize
 import Data.Time
 import Data.ByteString (ByteString)
-import Control.Concurrent (forkIO, killThread, threadDelay)
-import Control.Monad (forever, guard)
+import Control.Monad (guard)
 import Yesod.Core.Types
 import Yesod.Core.Internal.Util
-import qualified Data.IORef as I
 import Control.AutoUpdate
 
 encodeClientSession :: CS.Key
@@ -63,7 +61,7 @@ clientSessionDateCacher validity = do
       , updateFreq   = 10000000 -- 10s
       }
 
-    return $! (getClientSessionDateCache, return ())
+    return (getClientSessionDateCache, return ())
   where
     getUpdated = do
       now <- getCurrentTime
diff --git a/yesod-core/Yesod/Core/Internal/TH.hs b/yesod-core/Yesod/Core/Internal/TH.hs
index 52ab20c9..207137c4 100644
--- a/yesod-core/Yesod/Core/Internal/TH.hs
+++ b/yesod-core/Yesod/Core/Internal/TH.hs
@@ -16,7 +16,10 @@ import qualified Network.Wai as W
 
 import Data.ByteString.Lazy.Char8 ()
 import Data.List (foldl')
-import Control.Monad (replicateM)
+#if __GLASGOW_HASKELL__ < 710
+import Control.Applicative ((<$>))
+#endif
+import Control.Monad (replicateM, void)
 import Data.Either (partitionEithers)
 
 import Yesod.Routes.TH
@@ -45,15 +48,15 @@ mkYesodWith name args = fmap (uncurry (++)) . mkYesodGeneral name args False ret
 -- monolithic file into smaller parts. Use this function, paired with
 -- 'mkYesodDispatch', to do just that.
 mkYesodData :: String -> [ResourceTree String] -> Q [Dec]
-mkYesodData name res = mkYesodDataGeneral name False res
+mkYesodData name = mkYesodDataGeneral name False
 
 mkYesodSubData :: String -> [ResourceTree String] -> Q [Dec]
-mkYesodSubData name res = mkYesodDataGeneral name True res
+mkYesodSubData name = mkYesodDataGeneral name True
 
 mkYesodDataGeneral :: String -> Bool -> [ResourceTree String] -> Q [Dec]
 mkYesodDataGeneral name isSub res = do
     let (name':rest) = words name
-    fmap fst $ mkYesodGeneral name' (fmap Left rest) isSub return res
+    fst <$> mkYesodGeneral name' (fmap Left rest) isSub return res
 
 -- | See 'mkYesodData'.
 mkYesodDispatch :: String -> [ResourceTree String] -> Q [Dec]
@@ -150,8 +153,8 @@ mkMDS f rh = MkDispatchSettings
     , mdsGetPathInfo = [|W.pathInfo|]
     , mdsSetPathInfo = [|\p r -> r { W.pathInfo = p }|]
     , mdsMethod = [|W.requestMethod|]
-    , mds404 = [|notFound >> return ()|]
-    , mds405 = [|badMethod >> return ()|]
+    , mds404 = [|void notFound|]
+    , mds405 = [|void badMethod|]
     , mdsGetHandler = defaultGetHandler
     , mdsUnwrapper = f
     }
diff --git a/yesod-core/Yesod/Core/Internal/Util.hs b/yesod-core/Yesod/Core/Internal/Util.hs
index 96d87073..204602c7 100644
--- a/yesod-core/Yesod/Core/Internal/Util.hs
+++ b/yesod-core/Yesod/Core/Internal/Util.hs
@@ -14,8 +14,6 @@ import qualified Data.Text      as T
 import           Data.Time      (Day (ModifiedJulianDay, toModifiedJulianDay),
                                  DiffTime, UTCTime (..), formatTime,
                                  getCurrentTime, addUTCTime)
-import           Control.Monad  (liftM)
-
 #if MIN_VERSION_time(1,5,0)
 import           Data.Time      (defaultTimeLocale)
 #else
@@ -58,4 +56,4 @@ formatRFC822 = T.pack . formatTime defaultTimeLocale "%a, %d %b %Y %H:%M:%S %z"
 date on a resource that never expires. See RFC 2616 section 14.21 for details.
 -}
 getCurrentMaxExpiresRFC1123 :: IO T.Text
-getCurrentMaxExpiresRFC1123 = liftM (formatRFC1123 . addUTCTime (60*60*24*365)) getCurrentTime
+getCurrentMaxExpiresRFC1123 = fmap (formatRFC1123 . addUTCTime (60*60*24*365)) getCurrentTime
diff --git a/yesod-core/Yesod/Core/Types.hs b/yesod-core/Yesod/Core/Types.hs
index 6ab28dfd..f364f44a 100644
--- a/yesod-core/Yesod/Core/Types.hs
+++ b/yesod-core/Yesod/Core/Types.hs
@@ -20,8 +20,7 @@ import           Control.Arrow                      (first)
 import           Control.Exception                  (Exception)
 import           Control.Monad                      (liftM, ap)
 import           Control.Monad.Base                 (MonadBase (liftBase))
-import           Control.Monad.Catch                (MonadCatch (..))
-import           Control.Monad.Catch                (MonadMask (..))
+import           Control.Monad.Catch                (MonadMask (..), MonadCatch (..))
 import           Control.Monad.IO.Class             (MonadIO (liftIO))
 import           Control.Monad.Logger               (LogLevel, LogSource,
                                                      MonadLogger (..))
@@ -172,7 +171,7 @@ data ScriptLoadPosition master
 type BottomOfHeadAsync master
        = [Text] -- ^ urls to load asynchronously
       -> Maybe (HtmlUrl (Route master)) -- ^ widget of js to run on async completion
-      -> (HtmlUrl (Route master)) -- ^ widget to insert at the bottom of <head>
+      -> HtmlUrl (Route master) -- ^ widget to insert at the bottom of <head>
 
 type Texts = [Text]
 
@@ -264,7 +263,7 @@ instance (a ~ (), Monad m) => Semigroup (WidgetT site m a)
 -- @getHomeR = do defaultLayout "Widget text"@
 instance (Monad m, a ~ ()) => IsString (WidgetT site m a) where
     fromString = toWidget . toHtml . T.pack
-      where toWidget x = WidgetT $ const $ return $ ((), GWData (Body (const x))
+      where toWidget x = WidgetT $ const $ return ((), GWData (Body (const x))
                          mempty mempty mempty mempty mempty mempty)
 
 type RY master = Route master -> [(Text, Text)] -> Text
@@ -422,15 +421,15 @@ instance MonadBaseControl b m => MonadBaseControl b (WidgetT site m) where
     type StM (WidgetT site m) a = StM m (a, GWData (Route site))
     liftBaseWith f = WidgetT $ \reader' ->
         liftBaseWith $ \runInBase ->
-            liftM (\x -> (x, mempty))
+            fmap (\x -> (x, mempty))
             (f $ runInBase . flip unWidgetT reader')
     restoreM = WidgetT . const . restoreM
 #else
     data StM (WidgetT site m) a = StW (StM m (a, GWData (Route site)))
     liftBaseWith f = WidgetT $ \reader' ->
         liftBaseWith $ \runInBase ->
-            liftM (\x -> (x, mempty))
-            (f $ liftM StW . runInBase . flip unWidgetT reader')
+            fmap (\x -> (x, mempty))
+            (f $ fmap StW . runInBase . flip unWidgetT reader')
     restoreM (StW base) = WidgetT $ const $ restoreM base
 #endif
 instance Monad m => MonadReader site (WidgetT site m) where
@@ -464,11 +463,11 @@ instance MonadMask m => MonadMask (WidgetT site m) where
       where q u (WidgetT b) = WidgetT (u . b)
 
 instance (Applicative m, MonadIO m, MonadBase IO m, MonadThrow m) => MonadResource (WidgetT site m) where
-    liftResourceT f = WidgetT $ \hd -> liftIO $ fmap (, mempty) $ runInternalState f (handlerResource hd)
+    liftResourceT f = WidgetT $ \hd -> liftIO $ (, mempty) <$> runInternalState f (handlerResource hd)
 
 instance MonadIO m => MonadLogger (WidgetT site m) where
     monadLoggerLog a b c d = WidgetT $ \hd ->
-        liftIO $ fmap (, mempty) $ rheLog (handlerEnv hd) a b c (toLogStr d)
+        liftIO $ (, mempty) <$> rheLog (handlerEnv hd) a b c (toLogStr d)
 
 #if MIN_VERSION_monad_logger(0, 3, 10)
 instance MonadIO m => MonadLoggerIO (WidgetT site m) where
@@ -522,7 +521,7 @@ instance MonadBaseControl b m => MonadBaseControl b (HandlerT site m) where
     data StM (HandlerT site m) a = StH (StM m a)
     liftBaseWith f = HandlerT $ \reader' ->
         liftBaseWith $ \runInBase ->
-            f $ liftM StH . runInBase . (\(HandlerT r) -> r reader')
+            f $ fmap StH . runInBase . (\(HandlerT r) -> r reader')
     restoreM (StH base) = HandlerT $ const $ restoreM base
 #endif
 
diff --git a/yesod-core/Yesod/Core/Widget.hs b/yesod-core/Yesod/Core/Widget.hs
index 481199ee..2fa3f9af 100644
--- a/yesod-core/Yesod/Core/Widget.hs
+++ b/yesod-core/Yesod/Core/Widget.hs
@@ -57,9 +57,12 @@ import Text.Cassius
 import Text.Julius
 import Yesod.Routes.Class
 import Yesod.Core.Handler (getMessageRender, getUrlRenderParams)
+#if __GLASGOW_HASKELL__ < 710
+import Control.Applicative ((<$>))
+#endif
+import Control.Monad (liftM)
 import Control.Monad.IO.Class (MonadIO, liftIO)
 import Text.Shakespeare.I18N (RenderMessage)
-import Control.Monad (liftM)
 import Data.Text (Text)
 import qualified Data.Map as Map
 import Language.Haskell.TH.Quote (QuasiQuoter)
@@ -232,7 +235,7 @@ rules = do
     let ur f = do
             let env = NP.Env
                     (Just $ helper [|getUrlRenderParams|])
-                    (Just $ helper [|liftM (toHtml .) getMessageRender|])
+                    (Just $ helper [|fmap (toHtml .) getMessageRender|])
             f env
     return $ NP.HamletRules ah ur $ \_ b -> return $ ah `AppE` b
 
@@ -272,16 +275,16 @@ widgetToParentWidget (WidgetT f) = HandlerT $ \hd -> do
 
 liftGWD :: (child -> parent) -> GWData child -> GWData parent
 liftGWD tp gwd = GWData
-    { gwdBody = fixBody $ gwdBody gwd
-    , gwdTitle = gwdTitle gwd
-    , gwdScripts = fixUnique fixScript $ gwdScripts gwd
+    { gwdBody        = fixBody $ gwdBody gwd
+    , gwdTitle       = gwdTitle gwd
+    , gwdScripts     = fixUnique fixScript $ gwdScripts gwd
     , gwdStylesheets = fixUnique fixStyle $ gwdStylesheets gwd
-    , gwdCss = fmap fixCss $ gwdCss gwd
-    , gwdJavascript = fmap fixJS $ gwdJavascript gwd
-    , gwdHead = fixHead $ gwdHead gwd
+    , gwdCss         = fixCss <$> gwdCss gwd
+    , gwdJavascript  = fixJS <$> gwdJavascript gwd
+    , gwdHead        = fixHead $ gwdHead gwd
     }
   where
-    fixRender f route params = f (tp route) params
+    fixRender f route = f (tp route)
 
     fixBody (Body h) = Body $ h . fixRender
     fixHead (Head h) = Head $ h . fixRender
diff --git a/yesod-core/Yesod/Routes/TH.hs b/yesod-core/Yesod/Routes/TH.hs
index 7b2e50b7..fc2a6c20 100644
--- a/yesod-core/Yesod/Routes/TH.hs
+++ b/yesod-core/Yesod/Routes/TH.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE TemplateHaskell #-}
 module Yesod.Routes.TH
     ( module Yesod.Routes.TH.Types
       -- * Functions
diff --git a/yesod-core/Yesod/Routes/TH/RenderRoute.hs b/yesod-core/Yesod/Routes/TH/RenderRoute.hs
index d7266e57..70b33a05 100644
--- a/yesod-core/Yesod/Routes/TH/RenderRoute.hs
+++ b/yesod-core/Yesod/Routes/TH/RenderRoute.hs
@@ -55,7 +55,7 @@ mkRouteCons rttypes =
       where
         con = NormalC (mkName name)
             $ map (\x -> (notStrict, x))
-            $ concat [singles, [ConT $ mkName name]]
+            $ singles ++ [ConT $ mkName name]
 
         singles = concatMap toSingle pieces
         toSingle Static{} = []
@@ -99,7 +99,7 @@ mkRenderRouteClauses =
         dyns <- replicateM cnt $ newName "dyn"
         sub <-
             case resourceDispatch res of
-                Subsite{} -> fmap return $ newName "sub"
+                Subsite{} -> return <$> newName "sub"
                 _ -> return []
         let pat = ConP (mkName $ resourceName res) $ map VarP $ dyns ++ sub
 
@@ -136,7 +136,7 @@ mkRenderRouteClauses =
     mkPieces _ _ [] _ = []
     mkPieces toText tsp (Static s:ps) dyns = toText s : mkPieces toText tsp ps dyns
     mkPieces toText tsp (Dynamic{}:ps) (d:dyns) = tsp `AppE` VarE d : mkPieces toText tsp ps dyns
-    mkPieces _ _ ((Dynamic _) : _) [] = error "mkPieces 120"
+    mkPieces _ _ (Dynamic _ : _) [] = error "mkPieces 120"
 
 -- | Generate the 'RenderRoute' instance.
 --
diff --git a/yesod-core/Yesod/Routes/TH/RouteAttrs.hs b/yesod-core/Yesod/Routes/TH/RouteAttrs.hs
index 5ab7cde3..56e142e9 100644
--- a/yesod-core/Yesod/Routes/TH/RouteAttrs.hs
+++ b/yesod-core/Yesod/Routes/TH/RouteAttrs.hs
@@ -10,6 +10,9 @@ import Yesod.Routes.Class
 import Language.Haskell.TH.Syntax
 import Data.Set (fromList)
 import Data.Text (pack)
+#if __GLASGOW_HASKELL__ < 710
+import Control.Applicative ((<$>))
+#endif
 
 mkRouteAttrsInstance :: Type -> [ResourceTree a] -> Q Dec
 mkRouteAttrsInstance typ ress = do
@@ -19,11 +22,11 @@ mkRouteAttrsInstance typ ress = do
         ]
 
 goTree :: (Pat -> Pat) -> ResourceTree a -> Q [Clause]
-goTree front (ResourceLeaf res) = fmap return $ goRes front res
+goTree front (ResourceLeaf res) = return <$> goRes front res
 goTree front (ResourceParent name _check pieces trees) =
-    fmap concat $ mapM (goTree front') trees
+    concat <$> mapM (goTree front') trees
   where
-    ignored = ((replicate toIgnore WildP ++) . return)
+    ignored = (replicate toIgnore WildP ++) . return
     toIgnore = length $ filter isDynamic pieces
     isDynamic Dynamic{} = True
     isDynamic Static{} = False
diff --git a/yesod-core/Yesod/Routes/TH/Types.hs b/yesod-core/Yesod/Routes/TH/Types.hs
index 242c6077..369598e6 100644
--- a/yesod-core/Yesod/Routes/TH/Types.hs
+++ b/yesod-core/Yesod/Routes/TH/Types.hs
@@ -53,11 +53,11 @@ data Piece typ = Static String | Dynamic typ
     deriving Show
 
 instance Functor Piece where
-    fmap _ (Static s) = (Static s)
+    fmap _ (Static s)  = Static s
     fmap f (Dynamic t) = Dynamic (f t)
 
 instance Lift t => Lift (Piece t) where
-    lift (Static s) = [|Static $(lift s)|]
+    lift (Static s)  = [|Static  $(lift s)|]
     lift (Dynamic t) = [|Dynamic $(lift t)|]
 
 data Dispatch typ =
diff --git a/yesod-core/test/YesodCoreTest/Cache.hs b/yesod-core/test/YesodCoreTest/Cache.hs
index ca472ec2..5b77c1ba 100644
--- a/yesod-core/test/YesodCoreTest/Cache.hs
+++ b/yesod-core/test/YesodCoreTest/Cache.hs
@@ -13,8 +13,6 @@ import Yesod.Core
 import Data.IORef.Lifted
 import Data.Typeable (Typeable)
 import qualified Data.ByteString.Lazy.Char8 as L8
-import Data.Text (Text)
-import Data.Text.Encoding (encodeUtf8)
 
 data C = C
 
diff --git a/yesod-core/test/YesodCoreTest/ErrorHandling.hs b/yesod-core/test/YesodCoreTest/ErrorHandling.hs
index 609c8e60..e62e1841 100644
--- a/yesod-core/test/YesodCoreTest/ErrorHandling.hs
+++ b/yesod-core/test/YesodCoreTest/ErrorHandling.hs
@@ -9,11 +9,10 @@ import Yesod.Core
 import Test.Hspec
 import Network.Wai
 import Network.Wai.Test
-import Text.Hamlet (hamlet)
 import qualified Data.ByteString.Lazy as L
 import qualified Data.ByteString.Char8 as S8
 import Control.Exception (SomeException, try)
-import Network.HTTP.Types (mkStatus)
+import Network.HTTP.Types (Status, mkStatus)
 import Blaze.ByteString.Builder (Builder, fromByteString, toLazyByteString)
 import Data.Monoid (mconcat)
 import Data.Text (Text, pack)
@@ -40,6 +39,7 @@ mkYesod "App" [parseRoutes|
 /good-builder GoodBuilderR GET
 |]
 
+overrideStatus :: Status
 overrideStatus = mkStatus 15 "OVERRIDE"
 
 instance Yesod App where
diff --git a/yesod-core/test/YesodCoreTest/InternalRequest.hs b/yesod-core/test/YesodCoreTest/InternalRequest.hs
index f018c4f4..b29bfd54 100644
--- a/yesod-core/test/YesodCoreTest/InternalRequest.hs
+++ b/yesod-core/test/YesodCoreTest/InternalRequest.hs
@@ -2,10 +2,7 @@
 module YesodCoreTest.InternalRequest (internalRequestTest) where
 
 import Data.List (nub)
-import System.Random (StdGen, mkStdGen)
-
 import Network.Wai as W
-import Network.Wai.Test
 import Yesod.Core.Internal (randomString, parseWaiRequest)
 import Test.Hspec
 import Data.Monoid (mempty)
diff --git a/yesod-core/test/YesodCoreTest/Links.hs b/yesod-core/test/YesodCoreTest/Links.hs
index 22ff5363..7ea42a71 100644
--- a/yesod-core/test/YesodCoreTest/Links.hs
+++ b/yesod-core/test/YesodCoreTest/Links.hs
@@ -6,7 +6,6 @@ module YesodCoreTest.Links (linksTest, Widget) where
 import Test.Hspec
 
 import Yesod.Core
-import Text.Hamlet
 import Network.Wai
 import Network.Wai.Test
 import Data.Text (Text)
diff --git a/yesod-core/test/YesodCoreTest/Media.hs b/yesod-core/test/YesodCoreTest/Media.hs
index 3b2ac9c5..0904bfe1 100644
--- a/yesod-core/test/YesodCoreTest/Media.hs
+++ b/yesod-core/test/YesodCoreTest/Media.hs
@@ -8,7 +8,6 @@ import Test.Hspec
 import Yesod.Core
 import Network.Wai
 import Network.Wai.Test
-import Text.Lucius
 import YesodCoreTest.MediaData
 
 mkYesodDispatch "Y" resourcesY
diff --git a/yesod-core/test/YesodCoreTest/NoOverloadedStringsSub.hs b/yesod-core/test/YesodCoreTest/NoOverloadedStringsSub.hs
index 510ca3c9..e8be9c14 100644
--- a/yesod-core/test/YesodCoreTest/NoOverloadedStringsSub.hs
+++ b/yesod-core/test/YesodCoreTest/NoOverloadedStringsSub.hs
@@ -8,7 +8,6 @@
 module YesodCoreTest.NoOverloadedStringsSub where
 
 import Yesod.Core
-import Network.Wai
 import Yesod.Core.Types
 
 data Subsite = Subsite (forall master. Yesod master => YesodSubRunnerEnv Subsite master (HandlerT master IO) -> Application)
diff --git a/yesod-core/test/YesodCoreTest/Widget.hs b/yesod-core/test/YesodCoreTest/Widget.hs
index f3c0717e..2b16e543 100644
--- a/yesod-core/test/YesodCoreTest/Widget.hs
+++ b/yesod-core/test/YesodCoreTest/Widget.hs
@@ -6,10 +6,6 @@ module YesodCoreTest.Widget (widgetTest) where
 import Test.Hspec
 
 import Yesod.Core
-import Text.Julius
-import Text.Lucius
-import Text.Hamlet
-
 import Network.Wai
 import Network.Wai.Test