diff --git a/Yesod/Dispatch.hs b/Yesod/Dispatch.hs
index 74eaee8d..4afa3f3b 100644
--- a/Yesod/Dispatch.hs
+++ b/Yesod/Dispatch.hs
@@ -58,13 +58,13 @@ explodeHandler a b c d e f _ _ = runHandler a b (Just c) d e f
 mkYesodGeneral :: String -> [Name] -> Bool -> [Resource] -> Q [Dec]
 mkYesodGeneral name clazzes isSub res = do
     let name' = mkName name
-    let tySyn = TySynInstD ''Routes [ConT $ name'] (ConT $ mkName $ name ++ "Routes")
+    let tySyn = TySynInstD ''Routes [ConT name'] (ConT $ mkName $ name ++ "Routes")
     let site = mkName $ "site" ++ name
     let gsbod = NormalB $ VarE site
     let yes' = FunD (mkName "getSite") [Clause [] gsbod []]
     let yes = InstanceD [] (ConT ''YesodSite `AppT` ConT name') [yes']
     explode <- [|explodeHandler|]
-    CreateRoutesResult x _ z <- createRoutes $ CreateRoutesSettings
+    CreateRoutesResult x _ z <- createRoutes CreateRoutesSettings
                 { crRoutes = mkName $ name ++ "Routes"
                 , crApplication = ConT ''YesodApp
                 , crArgument = ConT $ mkName name
@@ -85,11 +85,11 @@ mkYesodGeneral name clazzes isSub res = do
                     `AppT` murl
                     `AppT` master
     let ctx = if isSub
-                then map (\c -> ClassP c [master]) clazzes
+                then map (flip ClassP [master]) clazzes
                 else []
-        tvs = if isSub then [PlainTV $ mkName "master"] else []
+        tvs = [PlainTV $ mkName "master" | isSub]
     let y' = SigD site $ ForallT tvs ctx yType
-    return $ (if isSub then id else (:) yes) $ [y', z, tySyn, x]
+    return $ (if isSub then id else (:) yes) [y', z, tySyn, x]
 
 toWaiApp :: Yesod y => y -> IO W.Application
 toWaiApp a = do
diff --git a/Yesod/Form.hs b/Yesod/Form.hs
index 0b7a80cf..cc0a3e0b 100644
--- a/Yesod/Form.hs
+++ b/Yesod/Form.hs
@@ -45,7 +45,7 @@ instance Functor Form where
 instance Applicative Form where
     pure x = Form $ \_ -> Right (Nothing, x)
     (Form f') <*> (Form x') = Form $ \l -> case (f' l, x' l) of
-        (Right (_, f), Right (_, x)) -> Right $ (Nothing, f x)
+        (Right (_, f), Right (_, x)) -> Right (Nothing, f x)
         (Left e1, Left e2) -> Left $ e1 ++ e2
         (Left e, _) -> Left e
         (_, Left e) -> Left e
@@ -75,7 +75,7 @@ runFormGet f = do
     runFormGeneric (getParams rr) f
 
 input :: ParamName -> Form [ParamValue]
-input pn = Form $ \l -> Right $ (Just pn, l pn)
+input pn = Form $ \l -> Right (Just pn, l pn)
 
 applyForm :: (x -> Either FormError y) -> Form x -> Form y
 applyForm f (Form x') =
diff --git a/Yesod/Handler.hs b/Yesod/Handler.hs
index ead83da9..17e16413 100644
--- a/Yesod/Handler.hs
+++ b/Yesod/Handler.hs
@@ -155,7 +155,7 @@ runHandler handler mrender sroute tomr ma tosa = YesodApp $ \eh rr cts -> do
             InternalError
           . (show :: Control.Exception.SomeException -> String)
     (headers, contents) <- Control.Exception.catch
-        (unHandler handler $ HandlerData
+        (unHandler handler HandlerData
             { handlerRequest = rr
             , handlerSub = tosa ma
             , handlerMaster = ma
diff --git a/Yesod/Helpers/Auth.hs b/Yesod/Helpers/Auth.hs
index 195c2d59..c9e9c10f 100644
--- a/Yesod/Helpers/Auth.hs
+++ b/Yesod/Helpers/Auth.hs
@@ -160,9 +160,7 @@ getDisplayName :: Rpxnow.Identifier -> String
 getDisplayName (Rpxnow.Identifier ident extra) = helper choices where
     choices = ["verifiedEmail", "email", "displayName", "preferredUsername"]
     helper [] = ident
-    helper (x:xs) = case lookup x extra of
-                        Nothing -> helper xs
-                        Just y -> y
+    helper (x:xs) = fromMaybe (helper xs) $ lookup x extra
 
 getCheck :: Yesod master => GHandler Auth master RepHtmlJson
 getCheck = do