diff --git a/Yesod.hs b/Yesod.hs
index 56f5b623..90fa85bd 100644
--- a/Yesod.hs
+++ b/Yesod.hs
@@ -10,7 +10,7 @@ module Yesod
     , module Yesod.Form
     , module Yesod.Hamlet
     , module Yesod.Json
-    , module Yesod.Contrib
+    , module Yesod.Formable
     , Application
     , liftIO
     , Routes
@@ -28,10 +28,10 @@ import Yesod.Dispatch
 
 import Yesod.Request
 import Yesod.Form hiding (Form)
+import Yesod.Formable
 import Yesod.Yesod
 import Yesod.Handler hiding (runHandler)
 import Network.Wai (Application)
 import Yesod.Hamlet
 import "transformers" Control.Monad.IO.Class (liftIO)
 import Web.Routes.Quasi (Routes)
-import Yesod.Contrib
diff --git a/Yesod/Contrib.hs b/Yesod/Contrib.hs
deleted file mode 100644
index a14027c0..00000000
--- a/Yesod/Contrib.hs
+++ /dev/null
@@ -1,9 +0,0 @@
-module Yesod.Contrib
-    ( module Yesod.Contrib.Formable
-    , module Yesod.Contrib.Crud
-    , module Yesod.Contrib.Persist
-    ) where
-
-import Yesod.Contrib.Formable hiding (runForm)
-import Yesod.Contrib.Crud
-import Yesod.Contrib.Persist
diff --git a/Yesod/Contrib/Persist.hs b/Yesod/Contrib/Persist.hs
deleted file mode 100644
index fdb36318..00000000
--- a/Yesod/Contrib/Persist.hs
+++ /dev/null
@@ -1,12 +0,0 @@
-{-# LANGUAGE TypeFamilies #-}
-module Yesod.Contrib.Persist
-    ( YesodPersist (..)
-    , Persist (..)
-    ) where
-
-import Yesod.Handler
-import Database.Persist
-
-class YesodPersist y where
-    type YesodDB y :: (* -> *) -> * -> *
-    runDB :: YesodDB y (GHandler sub y) a -> GHandler sub y a
diff --git a/Yesod/Dispatch.hs b/Yesod/Dispatch.hs
index 719198f1..0b26ba5c 100644
--- a/Yesod/Dispatch.hs
+++ b/Yesod/Dispatch.hs
@@ -55,8 +55,10 @@ import Data.Time
 import Control.Monad
 import Data.Maybe
 import Web.ClientSession
+import qualified Web.ClientSession as CS
 
 import Data.Serialize
+import qualified Data.Serialize as Ser
 import Network.Wai.Parse
 
 #if TEST
@@ -336,7 +338,7 @@ headerToPair _ (DeleteCookie key) =
 headerToPair _ (Header key value) =
     (W.responseHeaderFromBS $ S.fromString key, S.fromString value)
 
-encodeSession :: Key
+encodeSession :: CS.Key
               -> UTCTime -- ^ expire time
               -> B.ByteString -- ^ remote host
               -> [(String, String)] -- ^ session
@@ -344,7 +346,7 @@ encodeSession :: Key
 encodeSession key expire rhost session' =
     encrypt key $ encode $ SessionCookie expire rhost session'
 
-decodeSession :: Key
+decodeSession :: CS.Key
               -> UTCTime -- ^ current time
               -> B.ByteString -- ^ remote host field
               -> B.ByteString -- ^ cookie value
@@ -363,8 +365,8 @@ instance Serialize SessionCookie where
     put (SessionCookie a b c) = putTime a >> put b >> put c
     get = do
         a <- getTime
-        b <- get
-        c <- get
+        b <- Ser.get
+        c <- Ser.get
         return $ SessionCookie a b c
 
 putTime :: Putter UTCTime
@@ -375,8 +377,8 @@ putTime t@(UTCTime d _) = do
 
 getTime :: Get UTCTime
 getTime = do
-    d <- get
-    ndt <- get
+    d <- Ser.get
+    ndt <- Ser.get
     return $ fromRational ndt `addUTCTime` UTCTime (ModifiedJulianDay d) 0
 
 #if TEST
diff --git a/Yesod/Contrib/Formable.hs b/Yesod/Formable.hs
similarity index 91%
rename from Yesod/Contrib/Formable.hs
rename to Yesod/Formable.hs
index 5af2ca48..3a31a9cd 100644
--- a/Yesod/Contrib/Formable.hs
+++ b/Yesod/Formable.hs
@@ -3,12 +3,24 @@
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE TemplateHaskell #-}
 {-# LANGUAGE TypeSynonymInstances #-}
-module Yesod.Contrib.Formable where
+module Yesod.Formable
+    ( Form (..)
+    , Formlet
+    , SealedForm (..)
+    , SealedFormlet
+    , runForm
+    , runIncr
+    , Formable (..)
+    , Fieldable (..)
+    , deriveFormable
+    , share2
+    , wrapperRow
+    , sealFormlet
+    ) where
 
 import Text.Hamlet
 import Data.Time (Day)
 import Control.Applicative
-import Web.Routes.Quasi (SinglePiece)
 import Database.Persist (Persistable)
 import Data.Char (isAlphaNum)
 import Language.Haskell.TH.Syntax
@@ -19,6 +31,17 @@ import Control.Arrow (first)
 import Data.Maybe (fromMaybe)
 import Data.Monoid (mempty, mappend)
 import qualified Data.ByteString.Lazy.UTF8
+import Yesod.Request
+import Yesod.Handler
+import Control.Monad.IO.Class (liftIO)
+import Web.Routes.Quasi
+
+runForm :: SealedForm (Routes y) a
+        -> GHandler sub y (Either [String] a, Hamlet (Routes y))
+runForm f = do
+    req <- getRequest
+    (pp, _) <- liftIO $ reqRequestBody req
+    return $ fst $ runIncr (runSealedForm f pp) 1
 
 type Env = [(String, String)]
 
@@ -39,9 +62,7 @@ instance Functor FormResult where
     fmap _ (FormFailure errs) = FormFailure errs
     fmap f (FormSuccess a) = FormSuccess $ f a
 
-newtype Form url a = Form
-    { runForm :: Env -> Incr (FormResult a, Hamlet url)
-    }
+newtype Form url a = Form (Env -> Incr (FormResult a, Hamlet url))
 type Formlet url a = Maybe a -> Form url a
 
 newtype SealedForm url a = SealedForm
diff --git a/Yesod/Contrib/Crud.hs b/Yesod/Helpers/Crud.hs
similarity index 92%
rename from Yesod/Contrib/Crud.hs
rename to Yesod/Helpers/Crud.hs
index 6da09ded..24ba65ca 100644
--- a/Yesod/Contrib/Crud.hs
+++ b/Yesod/Helpers/Crud.hs
@@ -1,28 +1,21 @@
 {-# LANGUAGE TypeFamilies, QuasiQuotes, TemplateHaskell #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE Rank2Types #-}
-module Yesod.Contrib.Crud where
+module Yesod.Helpers.Crud
+    ( Item (..)
+    , Crud (..)
+    , defaultCrud
+    , siteCrud
+    ) where
 
 import Yesod.Yesod
 import Yesod.Dispatch
 import Yesod.Content
 import Yesod.Handler
-import Yesod.Request
 import Text.Hamlet
-import Control.Monad.IO.Class (liftIO)
-import Web.Routes.Quasi
-import Database.Persist
-import Yesod.Contrib.Formable hiding (runForm)
-import Yesod.Contrib.Persist
+import Yesod.Formable
 import Data.Monoid (mempty)
 
-runForm :: SealedForm (Routes y) a
-        -> GHandler sub y (Either [String] a, Hamlet (Routes y))
-runForm f = do
-    req <- getRequest
-    (pp, _) <- liftIO $ reqRequestBody req
-    return $ fst $ runIncr (runSealedForm f pp) 1
-
 class Formable a => Item a where
     itemTitle :: a -> String
 
diff --git a/Yesod/Yesod.hs b/Yesod/Yesod.hs
index b75eee0d..3cf87abe 100644
--- a/Yesod/Yesod.hs
+++ b/Yesod/Yesod.hs
@@ -1,10 +1,14 @@
 {-# LANGUAGE QuasiQuotes #-}
 {-# LANGUAGE RankNTypes #-}
+{-# LANGUAGE TypeFamilies #-}
 -- | The basic typeclass for a Yesod application.
 module Yesod.Yesod
     ( -- * Type classes
       Yesod (..)
     , YesodSite (..)
+      -- ** Persistence
+    , YesodPersist (..)
+    , Persist (..)
       -- * Convenience functions
     , applyLayout
     , applyLayoutJson
@@ -19,9 +23,11 @@ import Yesod.Handler
 import qualified Network.Wai as W
 import Yesod.Json
 import Yesod.Internal
-import Web.ClientSession (getKey, defaultKeyFile, Key)
+import Web.ClientSession (getKey, defaultKeyFile)
+import qualified Web.ClientSession as CS
 import Data.Monoid (mempty)
 import Data.ByteString.UTF8 (toString)
+import Database.Persist (Persist (..))
 
 import Web.Routes.Quasi (QuasiSite (..), Routes)
 
@@ -46,7 +52,7 @@ class Yesod a where
     approot :: a -> String
 
     -- | The encryption key to be used for encrypting client sessions.
-    encryptKey :: a -> IO Key
+    encryptKey :: a -> IO CS.Key
     encryptKey _ = getKey defaultKeyFile
 
     -- | Number of minutes before a client session times out. Defaults to
@@ -162,3 +168,7 @@ defaultErrorHandler (BadMethod m) =
 %h1 Method Not Supported
 %p Method "$string.m$" not supported
 |]
+
+class YesodPersist y where
+    type YesodDB y :: (* -> *) -> * -> *
+    runDB :: YesodDB y (GHandler sub y) a -> GHandler sub y a
diff --git a/yesod.cabal b/yesod.cabal
index 182222f5..f321c799 100644
--- a/yesod.cabal
+++ b/yesod.cabal
@@ -58,6 +58,7 @@ library
                      Yesod.Content
                      Yesod.Dispatch
                      Yesod.Form
+                     Yesod.Formable
                      Yesod.Hamlet
                      Yesod.Handler
                      Yesod.Internal
@@ -66,13 +67,10 @@ library
                      Yesod.Yesod
                      Yesod.Helpers.AtomFeed
                      Yesod.Helpers.Auth
+                     Yesod.Helpers.Crud
                      Yesod.Helpers.Sitemap
                      Yesod.Helpers.Static
-                     Yesod.Contrib
-                     Yesod.Contrib.Crud
-                     Yesod.Contrib.Formable
-                     Yesod.Contrib.Persist
-    ghc-options:     -Wall
+    ghc-options:     -Wall -Werror
 
 executable             runtests
     if flag(buildtests)