diff --git a/sources.txt b/sources.txt
index b7eec6ed..991f9b9d 100644
--- a/sources.txt
+++ b/sources.txt
@@ -1,4 +1,3 @@
-./yesod-routes
 ./yesod-core
 ./yesod-static
 ./yesod-persistent
diff --git a/yesod-auth/Yesod/Auth.hs b/yesod-auth/Yesod/Auth.hs
index ddfd0ed1..91d820e8 100644
--- a/yesod-auth/Yesod/Auth.hs
+++ b/yesod-auth/Yesod/Auth.hs
@@ -161,7 +161,6 @@ class (Yesod master, PathPiece (AuthId master), RenderMessage master FormMessage
     -- Since 1.2.0
     maybeAuthId :: HandlerT master IO (Maybe (AuthId master))
 
-#if MIN_VERSION_persistent(2, 0, 0)
     default maybeAuthId
         :: ( YesodAuth master
            , PersistEntityBackend val ~ YesodPersistBackend master
@@ -172,19 +171,6 @@ class (Yesod master, PathPiece (AuthId master), RenderMessage master FormMessage
            , Typeable val
            )
         => HandlerT master IO (Maybe (AuthId master))
-#else
-    default maybeAuthId
-        :: ( YesodAuth master
-           , PersistMonadBackend (b (HandlerT master IO)) ~ PersistEntityBackend val
-           , b ~ YesodPersistBackend master
-           , Key val ~ AuthId master
-           , PersistStore (b (HandlerT master IO))
-           , PersistEntity val
-           , YesodPersist master
-           , Typeable val
-           )
-        => HandlerT master IO (Maybe (AuthId master))
-#endif
     maybeAuthId = defaultMaybeAuthId
 
     -- | Called on login error for HTTP requests. By default, calls
@@ -206,7 +192,6 @@ credsKey = "_ID"
 -- 'maybeAuthIdRaw' for more information.
 --
 -- Since 1.1.2
-#if MIN_VERSION_persistent(2, 0, 0)
 defaultMaybeAuthId
           :: ( YesodAuth master
              , b ~ YesodPersistBackend master
@@ -217,18 +202,6 @@ defaultMaybeAuthId
              , YesodPersist master
              , Typeable val
              ) => HandlerT master IO (Maybe (AuthId master))
-#else
-defaultMaybeAuthId
-          :: ( YesodAuth master
-             , PersistMonadBackend (b (HandlerT master IO)) ~ PersistEntityBackend val
-             , b ~ YesodPersistBackend master
-             , Key val ~ AuthId master
-             , PersistStore (b (HandlerT master IO))
-             , PersistEntity val
-             , YesodPersist master
-             , Typeable val
-             ) => HandlerT master IO (Maybe (AuthId master))
-#endif
 defaultMaybeAuthId = do
     ms <- lookupSession credsKey
     case ms of
@@ -238,7 +211,6 @@ defaultMaybeAuthId = do
                 Nothing -> return Nothing
                 Just aid -> fmap (fmap entityKey) $ cachedAuth aid
 
-#if MIN_VERSION_persistent(2, 0, 0)
 cachedAuth :: ( YesodAuth master
              , b ~ YesodPersistBackend master
              , b ~ PersistEntityBackend val
@@ -248,17 +220,6 @@ cachedAuth :: ( YesodAuth master
              , YesodPersist master
              , Typeable val
              ) => AuthId master -> HandlerT master IO (Maybe (Entity val))
-#else
-cachedAuth :: ( YesodAuth master
-             , PersistMonadBackend (b (HandlerT master IO)) ~ PersistEntityBackend val
-             , b ~ YesodPersistBackend master
-             , Key val ~ AuthId master
-             , PersistStore (b (HandlerT master IO))
-             , PersistEntity val
-             , YesodPersist master
-             , Typeable val
-             ) => AuthId master -> HandlerT master IO (Maybe (Entity val))
-#endif
 cachedAuth aid = runMaybeT $ do
     a <- MaybeT $ fmap unCachedMaybeAuth
                 $ cached
@@ -411,7 +372,6 @@ handlePluginR plugin pieces = do
 -- assumes that you are using a Persistent database.
 --
 -- Since 1.1.0
-#if MIN_VERSION_persistent(2, 0, 0)
 maybeAuth :: ( YesodAuth master
              , b ~ YesodPersistBackend master
              , b ~ PersistEntityBackend val
@@ -421,17 +381,6 @@ maybeAuth :: ( YesodAuth master
              , YesodPersist master
              , Typeable val
              ) => HandlerT master IO (Maybe (Entity val))
-#else
-maybeAuth :: ( YesodAuth master
-             , PersistMonadBackend (b (HandlerT master IO)) ~ PersistEntityBackend val
-             , b ~ YesodPersistBackend master
-             , Key val ~ AuthId master
-             , PersistStore (b (HandlerT master IO))
-             , PersistEntity val
-             , YesodPersist master
-             , Typeable val
-             ) => HandlerT master IO (Maybe (Entity val))
-#endif
 maybeAuth = runMaybeT $ do
     aid <- MaybeT maybeAuthId
     MaybeT $ cachedAuth aid
@@ -445,7 +394,6 @@ newtype CachedMaybeAuth val = CachedMaybeAuth { unCachedMaybeAuth :: Maybe val }
 -- full informatin on a given user.
 --
 -- Since 1.2.0
-#if MIN_VERSION_persistent(2, 0, 0)
 type YesodAuthPersist master =
     ( YesodAuth master
     , YesodPersistBackend master
@@ -456,18 +404,6 @@ type YesodAuthPersist master =
     , YesodPersist master
     , Typeable (AuthEntity master)
     )
-#else
-type YesodAuthPersist master =
-    ( YesodAuth master
-    , PersistMonadBackend (YesodPersistBackend master (HandlerT master IO))
-        ~ PersistEntityBackend (AuthEntity master)
-    , Key (AuthEntity master) ~ AuthId master
-    , PersistStore (YesodPersistBackend master (HandlerT master IO))
-    , PersistEntity (AuthEntity master)
-    , YesodPersist master
-    , Typeable (AuthEntity master)
-    )
-#endif
 
 -- | If the @AuthId@ for a given site is a persistent ID, this will give the
 -- value for that entity. E.g.:
@@ -477,10 +413,8 @@ type YesodAuthPersist master =
 --
 -- Since 1.2.0
 type AuthEntity master = KeyEntity (AuthId master)
-#if MIN_VERSION_persistent(2, 0, 0)
 type family KeyEntity key
 type instance KeyEntity (Key x) = x
-#endif
 
 -- | Similar to 'maybeAuthId', but redirects to a login page if user is not
 -- authenticated or responds with error 401 if this is an API client (expecting JSON).
diff --git a/yesod-bin/Devel.hs b/yesod-bin/Devel.hs
index af4a6959..feb4a8f4 100644
--- a/yesod-bin/Devel.hs
+++ b/yesod-bin/Devel.hs
@@ -66,17 +66,11 @@ import           GhcBuild                              (buildPackage,
 import qualified Config                                as GHC
 import           Data.Streaming.Network                (bindPortTCP)
 import           Network                               (withSocketsDo)
-#if MIN_VERSION_http_conduit(2, 0, 0)
 import           Network.HTTP.Conduit                  (conduitManagerSettings, newManager)
 import           Data.Default.Class                    (def)
-#else
-import           Network.HTTP.Conduit                  (def, newManager)
-#endif
 import           Network.HTTP.ReverseProxy             (ProxyDest (ProxyDest),
                                                         waiProxyToSettings, wpsTimeout, wpsOnExc)
-#if MIN_VERSION_http_reverse_proxy(0, 2, 0)
 import qualified Network.HTTP.ReverseProxy             as ReverseProxy
-#endif
 import           Network.HTTP.Types                    (status200, status503)
 import           Network.Socket                        (sClose)
 import           Network.Wai                           (responseLBS, requestHeaders)
@@ -130,11 +124,7 @@ cabalProgram opts | isCabalDev opts = "cabal-dev"
 -- 3001, give an appropriate message to the user.
 reverseProxy :: DevelOpts -> I.IORef Int -> IO ()
 reverseProxy opts iappPort = do
-#if MIN_VERSION_http_conduit(2, 0, 0)
     manager <- newManager conduitManagerSettings
-#else
-    manager <- newManager def
-#endif
     let refreshHtml = LB.fromChunks $ return $(embedFile "refreshing.html")
     let onExc _ req
             | maybe False (("application/json" `elem`) . parseHttpAccept)
@@ -154,18 +144,10 @@ reverseProxy opts iappPort = do
                 (const $ do
                     appPort <- liftIO $ I.readIORef iappPort
                     return $
-#if MIN_VERSION_http_reverse_proxy(0, 2, 0)
                         ReverseProxy.WPRProxyDest
-#else
-                        Right
-#endif
                         $ ProxyDest "127.0.0.1" appPort)
                 def
-#if MIN_VERSION_wai(3, 0, 0)
                     { wpsOnExc = \e req f -> onExc e req >>= f
-#else
-                    { wpsOnExc = onExc
-#endif
                     , wpsTimeout =
                         if proxyTimeout opts == 0
                             then Nothing
diff --git a/yesod-bin/Options.hs b/yesod-bin/Options.hs
index 62a2aa30..735702fd 100644
--- a/yesod-bin/Options.hs
+++ b/yesod-bin/Options.hs
@@ -76,15 +76,9 @@ injectDefaultP env path p@(OptP o)
      p <|> if any ((==Just "1") . getEnvValue env path) names then pure a else empty
   | otherwise = p
   where
-#if MIN_VERSION_optparse_applicative(0,6,0)
     right= ReadM . Right
     left = ReadM . Left
     either' f g (ReadM x) = either f g x
-#else
-    right = Right
-    left = Left
-    either' = either
-#endif
 injectDefaultP env path (MultP p1 p2) =
    MultP (injectDefaultP env path p1) (injectDefaultP env path p2)
 injectDefaultP env path (AltP p1 p2) =
diff --git a/yesod-bin/main.hs b/yesod-bin/main.hs
index deece976..80dd136c 100755
--- a/yesod-bin/main.hs
+++ b/yesod-bin/main.hs
@@ -15,11 +15,7 @@ import           Options                (injectDefaults)
 import qualified Paths_yesod_bin
 import           Scaffolding.Scaffolder
 
-#if MIN_VERSION_optparse_applicative(0,6,0)
 import           Options.Applicative.Types (ReadM (ReadM))
-#else
-import           Options.Applicative.Builder.Internal (Mod, OptionFields)
-#endif
 
 import           HsFile                 (mkHsFile)
 #ifndef WINDOWS
@@ -155,12 +151,6 @@ keterOptions = Keter <$> switch ( long "nobuild" <> short 'n' <> help "Skip rebu
 defaultRescan :: Int
 defaultRescan = 10
 
-#if MIN_VERSION_optparse_applicative(0,10,0)
-option' = option auto
-#else
-option' = option
-#endif
-
 develOptions :: Parser Command
 develOptions = Devel <$> switch ( long "disable-api"  <> short 'd'
                             <> help "Disable fast GHC API rebuilding")
@@ -168,7 +158,7 @@ develOptions = Devel <$> switch ( long "disable-api"  <> short 'd'
                             <> help "Run COMMAND after rebuild succeeds")
                      <*> optStr ( long "failure-hook" <> short 'f' <> metavar "COMMAND"
                             <> help "Run COMMAND when rebuild fails")
-                     <*> option' ( long "event-timeout" <> short 't' <> value defaultRescan <> metavar "N"
+                     <*> option auto ( long "event-timeout" <> short 't' <> value defaultRescan <> metavar "N"
                             <> help ("Force rescan of files every N seconds (default "
                                      ++ show defaultRescan
                                      ++ ", use -1 to rely on FSNotify alone)") )
@@ -178,9 +168,9 @@ develOptions = Devel <$> switch ( long "disable-api"  <> short 'd'
                                    <> help "ignore file changes in DIR" )
                               )
                      <*> extraCabalArgs
-                     <*> option' ( long "port" <> short 'p' <> value 3000 <> metavar "N"
+                     <*> option auto ( long "port" <> short 'p' <> value 3000 <> metavar "N"
                             <> help "Devel server listening port" )
-                     <*> option' ( long "proxy-timeout" <> short 'x' <> value 0 <> metavar "N"
+                     <*> option auto ( long "proxy-timeout" <> short 'x' <> value 0 <> metavar "N"
                             <> help "Devel server timeout before returning 'not ready' message (in seconds, 0 for none)" )
                      <*> switch ( long "disable-reverse-proxy" <> short 'n'
                             <> help "Disable reverse proxy" )
@@ -195,17 +185,9 @@ extraCabalArgs = many (strOption ( long "extra-cabal-arg" <> short 'e' <> metava
 -- | Optional @String@ argument
 optStr :: Mod OptionFields (Maybe String) -> Parser (Maybe String)
 optStr m =
-#if MIN_VERSION_optparse_applicative(0,10,0)
     nullOption (success . str) $ value Nothing <> m
-#else
-    nullOption $ value Nothing <> reader (success . str)  <> m
-#endif
   where
-#if MIN_VERSION_optparse_applicative(0,6,0)
     success = ReadM . Right
-#else
-    success = Right
-#endif
 
 -- | Like @rawSystem@, but exits if it receives a non-success result.
 rawSystem' :: String -> [String] -> IO ()
diff --git a/yesod-bin/yesod-bin.cabal b/yesod-bin/yesod-bin.cabal
index 20a821a3..46971b7b 100644
--- a/yesod-bin/yesod-bin.cabal
+++ b/yesod-bin/yesod-bin.cabal
@@ -70,7 +70,7 @@ executable             yesod
                      , system-fileio      >= 0.3          && < 0.4
                      , unordered-containers
                      , yaml               >= 0.8          && < 0.9
-                     , optparse-applicative >= 0.5
+                     , optparse-applicative >= 0.10
                      , fsnotify           >= 0.0          && < 0.2
                      , split              >= 0.2          && < 0.3
                      , file-embed
@@ -79,9 +79,9 @@ executable             yesod
                      , resourcet          >= 0.3          && < 1.2
                      , base64-bytestring
                      , lifted-base
-                     , http-reverse-proxy >= 0.1.1
+                     , http-reverse-proxy >= 0.4
                      , network
-                     , http-conduit
+                     , http-conduit       >= 2.1.4
                      , project-template   >= 0.1.1
                      , transformers
                      , warp               >= 1.3.7.5
diff --git a/yesod-core/Yesod/Core/Class/Handler.hs b/yesod-core/Yesod/Core/Class/Handler.hs
index a6e99647..e2577b3d 100644
--- a/yesod-core/Yesod/Core/Class/Handler.hs
+++ b/yesod-core/Yesod/Core/Class/Handler.hs
@@ -61,9 +61,6 @@ GOX(Monoid w, RWST r w s)
 GOX(Monoid w, Strict.RWST r w s)
 GO(Strict.StateT s)
 GOX(Monoid w, Strict.WriterT w)
-#if !MIN_VERSION_resourcet(1,1,0)
-GO(ExceptionT)
-#endif
 GO(Pipe l i o u)
 GO(ConduitM i o)
 #undef GO
@@ -87,9 +84,6 @@ GOX(Monoid w, RWST r w s)
 GOX(Monoid w, Strict.RWST r w s)
 GO(Strict.StateT s)
 GOX(Monoid w, Strict.WriterT w)
-#if !MIN_VERSION_resourcet(1,1,0)
-GO(ExceptionT)
-#endif
 GO(Pipe l i o u)
 GO(ConduitM i o)
 #undef GO
diff --git a/yesod-core/Yesod/Core/Class/Yesod.hs b/yesod-core/Yesod/Core/Class/Yesod.hs
index 8631d27e..8ccc4869 100644
--- a/yesod-core/Yesod/Core/Class/Yesod.hs
+++ b/yesod-core/Yesod/Core/Class/Yesod.hs
@@ -40,16 +40,9 @@ import           Data.Default                       (def)
 import           Network.Wai.Parse                  (lbsBackEnd,
                                                      tempFileBackEnd)
 import           System.IO                          (stdout)
-#if MIN_VERSION_fast_logger(2, 0, 0)
 import           Network.Wai.Logger                 (ZonedDate, clockDateCacher)
 import           System.Log.FastLogger
 import qualified GHC.IO.FD
-#else
-import           System.Log.FastLogger.Date         (ZonedDate)
-import           System.Log.FastLogger              (LogStr (..), Logger,
-                                                     loggerDate, loggerPutStr,
-                                                     mkLogger)
-#endif
 import           Text.Blaze                         (customAttribute, textTag,
                                                      toValue, (!))
 import           Text.Blaze                         (preEscapedToMarkup)
@@ -216,18 +209,10 @@ class RenderRoute site => Yesod site where
     --
     -- Default: Sends to stdout and automatically flushes on each write.
     makeLogger :: site -> IO Logger
-#if MIN_VERSION_fast_logger(2, 0, 0)
     makeLogger _ = do
-#if MIN_VERSION_fast_logger(2, 1, 0)
         loggerSet <- newLoggerSet defaultBufSize Nothing
-#else
-        loggerSet <- newLoggerSet defaultBufSize GHC.IO.FD.stdout
-#endif
         (getter, _) <- clockDateCacher
         return $! Logger loggerSet getter
-#else
-    makeLogger _ = mkLogger True stdout
-#endif
 
     -- | Send a message to the @Logger@ provided by @getLogger@.
     --
@@ -541,7 +526,6 @@ asyncHelper render scripts jscript jsLoc =
                     Nothing -> Nothing
                     Just j -> Just $ jelper j
 
-#if MIN_VERSION_fast_logger(2, 0, 0)
 formatLogMessage :: IO ZonedDate
                  -> Loc
                  -> LogSource
@@ -564,33 +548,6 @@ formatLogMessage getdate loc src level msg = do
         " @(" `mappend`
         toLogStr (fileLocationToString loc) `mappend`
         ")\n"
-#else
-formatLogMessage :: IO ZonedDate
-                 -> Loc
-                 -> LogSource
-                 -> LogLevel
-                 -> LogStr -- ^ message
-                 -> IO [LogStr]
-formatLogMessage getdate loc src level msg = do
-    now <- getdate
-    return
-        [ LB now
-        , LB " ["
-        , LS $
-            case level of
-                LevelOther t -> T.unpack t
-                _ -> drop 5 $ show level
-        , LS $
-            if T.null src
-                then ""
-                else "#" ++ T.unpack src
-        , LB "] "
-        , msg
-        , LB " @("
-        , LS $ fileLocationToString loc
-        , LB ")\n"
-        ]
-#endif
 
 -- | Customize the cookies used by the session backend.  You may
 -- use this function on your definition of 'makeSessionBackend'.
diff --git a/yesod-core/Yesod/Core/Content.hs b/yesod-core/Yesod/Core/Content.hs
index fa12f7f6..b6b5ffcf 100644
--- a/yesod-core/Yesod/Core/Content.hs
+++ b/yesod-core/Yesod/Core/Content.hs
@@ -63,9 +63,7 @@ import Text.Blaze.Html.Renderer.Utf8 (renderHtmlBuilder)
 import Data.Conduit (Source, Flush (Chunk), ResumableSource, mapOutput)
 import Control.Monad.Trans.Resource (ResourceT)
 import Data.Conduit.Internal (ResumableSource (ResumableSource))
-#if MIN_VERSION_conduit(1, 2, 0)
 import qualified Data.Conduit.Internal as CI
-#endif
 
 import qualified Data.Aeson as J
 import Data.Aeson.Encode (fromValue)
@@ -118,10 +116,8 @@ instance ToContent Css where
 instance ToContent Javascript where
     toContent = toContent . toLazyText . unJavascript
 
-#if MIN_VERSION_conduit(1, 2, 0)
 instance ToFlushBuilder builder => ToContent (CI.Pipe () () builder () (ResourceT IO) ()) where
     toContent src = ContentSource $ CI.ConduitM (CI.mapOutput toFlushBuilder src >>=)
-#endif
 
 instance ToFlushBuilder builder => ToContent (Source (ResourceT IO) builder) where
     toContent src = ContentSource $ mapOutput toFlushBuilder src
diff --git a/yesod-core/Yesod/Core/Dispatch.hs b/yesod-core/Yesod/Core/Dispatch.hs
index e0d1f0e6..9dcaf455 100644
--- a/yesod-core/Yesod/Core/Dispatch.hs
+++ b/yesod-core/Yesod/Core/Dispatch.hs
@@ -92,13 +92,8 @@ toWaiAppYre yre req =
   where
     site = yreSite yre
     sendRedirect :: Yesod master => master -> [Text] -> W.Application
-#if MIN_VERSION_wai(3, 0, 0)
     sendRedirect y segments' env sendResponse =
          sendResponse $ W.responseLBS status301
-#else
-    sendRedirect y segments' env =
-         return $ W.responseLBS status301
-#endif
                 [ ("Content-Type", "text/plain")
                 , ("Location", Blaze.ByteString.Builder.toByteString dest')
                 ] "Redirecting"
@@ -180,12 +175,7 @@ warp port site = do
                     (toLogStr $ "Exception from Warp: " ++ show e)
             }
   where
-    shouldLog' =
-#if MIN_VERSION_warp(2,1,3)
-        Network.Wai.Handler.Warp.defaultShouldDisplayException
-#else
-        const True
-#endif
+    shouldLog' = Network.Wai.Handler.Warp.defaultShouldDisplayException
 
 -- | A default set of middlewares.
 --
@@ -193,11 +183,7 @@ warp port site = do
 mkDefaultMiddlewares :: Logger -> IO W.Middleware
 mkDefaultMiddlewares logger = do
     logWare <- mkRequestLogger def
-#if MIN_VERSION_fast_logger(2, 0, 0)
         { destination = Network.Wai.Middleware.RequestLogger.Logger $ loggerSet logger
-#else
-        { destination = Logger logger
-#endif
         , outputFormat = Apache FromSocket
         }
     return $ logWare . defaultMiddlewaresNoLogging
diff --git a/yesod-core/Yesod/Core/Handler.hs b/yesod-core/Yesod/Core/Handler.hs
index d2b196b4..e975039f 100644
--- a/yesod-core/Yesod/Core/Handler.hs
+++ b/yesod-core/Yesod/Core/Handler.hs
@@ -92,12 +92,8 @@ module Yesod.Core.Handler
     , sendResponseCreated
     , sendWaiResponse
     , sendWaiApplication
-#if MIN_VERSION_wai(2, 1, 0)
     , sendRawResponse
-#endif
-#if MIN_VERSION_wai(3, 0, 0)
     , sendRawResponseNoConduit
-#endif
       -- * Different representations
       -- $representations
     , selectRep
@@ -206,21 +202,11 @@ 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
-#if MIN_VERSION_wai(2, 0, 0)
-#else
-              , ResourceT
-#endif
               )
-#if MIN_VERSION_wai(2, 0, 0)
 import qualified System.PosixCompat.Files as PC
-#endif
-#if MIN_VERSION_wai(2, 1, 0)
 import Control.Monad.Trans.Control (control, MonadBaseControl)
-#endif
 import Data.Conduit (Source, transPipe, Flush (Flush), yield, Producer
-#if MIN_VERSION_wai(2, 1, 0)
                     , Sink
-#endif
                    )
 
 get :: MonadHandler m => m GHState
@@ -257,41 +243,22 @@ runRequestBody = do
         Just rbc -> return rbc
         Nothing -> do
             rr <- waiRequest
-#if MIN_VERSION_wai_extra(2, 0, 1)
             internalState <- liftResourceT getInternalState
             rbc <- liftIO $ rbHelper upload rr internalState
-#elif MIN_VERSION_wai(2, 0, 0)
-            rbc <- liftIO $ rbHelper upload rr
-#else
-            rbc <- liftResourceT $ rbHelper upload rr
-#endif
             put x { ghsRBC = Just rbc }
             return rbc
 
-#if MIN_VERSION_wai(2, 0, 0)
 rbHelper :: FileUpload -> W.Request -> InternalState -> IO RequestBodyContents
 rbHelper upload req internalState =
-#else
-rbHelper :: FileUpload -> W.Request -> ResourceT IO RequestBodyContents
-rbHelper upload req =
-#endif
     case upload of
         FileUploadMemory s -> rbHelper' s mkFileInfoLBS req
-#if MIN_VERSION_wai_extra(2, 0, 1)
         FileUploadDisk s -> rbHelper' (s internalState) mkFileInfoFile req
-#else
-        FileUploadDisk s -> rbHelper' s mkFileInfoFile req
-#endif
         FileUploadSource s -> rbHelper' s mkFileInfoSource req
 
 rbHelper' :: NWP.BackEnd x
           -> (Text -> Text -> x -> FileInfo)
           -> W.Request
-#if MIN_VERSION_wai(2, 0, 0)
           -> IO ([(Text, Text)], [(Text, FileInfo)])
-#else
-          -> ResourceT IO ([(Text, Text)], [(Text, FileInfo)])
-#endif
 rbHelper' backend mkFI req =
     (map fix1 *** mapMaybe fix2) <$> (NWP.parseRequestBody backend req)
   where
@@ -375,11 +342,7 @@ handlerToIO =
           where
             oldReq    = handlerRequest oldHandlerData
             oldWaiReq = reqWaiRequest oldReq
-#if MIN_VERSION_wai(3, 0, 0)
             newWaiReq = oldWaiReq { W.requestBody = return mempty
-#else
-            newWaiReq = oldWaiReq { W.requestBody = mempty
-#endif
                                   , W.requestBodyLength = W.KnownLength 0
                                   }
         oldEnv = handlerEnv oldHandlerData
@@ -551,16 +514,12 @@ sendFilePart :: MonadHandler m
              -> Integer -- ^ count
              -> m a
 sendFilePart ct fp off count = do
-#if MIN_VERSION_wai(2, 0, 0)
     fs <- liftIO $ PC.getFileStatus fp
     handlerError $ HCSendFile ct fp $ Just W.FilePart
         { W.filePartOffset = off
         , W.filePartByteCount = count
         , W.filePartFileSize = fromIntegral $ PC.fileSize fs
         }
-#else
-    handlerError $ HCSendFile ct fp $ Just $ W.FilePart off count
-#endif
 
 -- | Bypass remaining handler code and output the given content with a 200
 -- status code.
@@ -593,7 +552,6 @@ sendWaiResponse = handlerError . HCWai
 sendWaiApplication :: MonadHandler m => W.Application -> m b
 sendWaiApplication = handlerError . HCWaiApp
 
-#if MIN_VERSION_wai(3, 0, 0)
 -- | Send a raw response without conduit. This is used for cases such as
 -- WebSockets. Requires WAI 3.0 or later, and a web server which supports raw
 -- responses (e.g., Warp).
@@ -609,9 +567,7 @@ sendRawResponseNoConduit raw = control $ \runInIO ->
   where
     fallback = W.responseLBS H.status500 [("Content-Type", "text/plain")]
         "sendRawResponse: backend does not support raw responses"
-#endif
 
-#if MIN_VERSION_wai(2, 1, 0)
 -- | Send a raw response. This is used for cases such as WebSockets. Requires
 -- WAI 2.1 or later, and a web server which supports raw responses (e.g.,
 -- Warp).
@@ -620,7 +576,6 @@ sendRawResponseNoConduit raw = control $ \runInIO ->
 sendRawResponse :: (MonadHandler m, MonadBaseControl IO m)
                 => (Source IO S8.ByteString -> Sink S8.ByteString IO () -> m ())
                 -> m a
-#if MIN_VERSION_wai(3, 0, 0)
 sendRawResponse raw = control $ \runInIO ->
     runInIO $ sendWaiResponse $ flip W.responseRaw fallback
     $ \src sink -> runInIO (raw (src' src) (CL.mapM_ sink)) >> return ()
@@ -632,15 +587,6 @@ sendRawResponse raw = control $ \runInIO ->
         unless (S.null bs) $ do
             yield bs
             src' src
-#else
-sendRawResponse raw = control $ \runInIO ->
-    runInIO $ sendWaiResponse $ flip W.responseRaw fallback
-    $ \src sink -> runInIO (raw src sink) >> return ()
-  where
-    fallback = W.responseLBS H.status500 [("Content-Type", "text/plain")]
-        "sendRawResponse: backend does not support raw responses"
-#endif
-#endif
 
 -- | Return a 404 not found page. Also denotes no handler available.
 notFound :: MonadHandler m => m a
@@ -1126,22 +1072,12 @@ provideRepType ct handler =
 rawRequestBody :: MonadHandler m => Source m S.ByteString
 rawRequestBody = do
     req <- lift waiRequest
-#if MIN_VERSION_wai(3, 0, 0)
     let loop = do
             bs <- liftIO $ W.requestBody req
             unless (S.null bs) $ do
                 yield bs
                 loop
     loop
-#else
-    transPipe
-#if MIN_VERSION_wai(2, 0, 0)
-        liftIO
-#else
-        liftResourceT
-#endif
-        (W.requestBody req)
-#endif
 
 -- | Stream the data from the file. Since Yesod 1.2, this has been generalized
 -- to work in any @MonadResource@.
diff --git a/yesod-core/Yesod/Core/Internal/Request.hs b/yesod-core/Yesod/Core/Internal/Request.hs
index ba2fd2fc..cf0d9351 100644
--- a/yesod-core/Yesod/Core/Internal/Request.hs
+++ b/yesod-core/Yesod/Core/Internal/Request.hs
@@ -48,7 +48,6 @@ import Data.IORef
 
 -- | Impose a limit on the size of the request body.
 limitRequestBody :: Word64 -> W.Request -> IO W.Request
-#if MIN_VERSION_wai(3, 0, 0)
 limitRequestBody maxLen req = do
     ref <- newIORef maxLen
     return req
@@ -63,24 +62,6 @@ limitRequestBody maxLen req = do
                     writeIORef ref remaining'
                     return bs
         }
-#else
-limitRequestBody maxLen req =
-    return req { W.requestBody = W.requestBody req $= limit maxLen }
-  where
-    tooLarge = liftIO $ throwIO $ HCWai tooLargeResponse
-
-    limit 0 = tooLarge
-    limit remaining =
-        await >>= maybe (return ()) go
-      where
-        go bs = do
-            let len = fromIntegral $ S8.length bs
-            if len > remaining
-                then tooLarge
-                else do
-                    yield bs
-                    limit $ remaining - len
-#endif
 
 tooLargeResponse :: W.Response
 tooLargeResponse = W.responseLBS
diff --git a/yesod-core/Yesod/Core/Internal/Response.hs b/yesod-core/Yesod/Core/Internal/Response.hs
index affa1a7b..83c57676 100644
--- a/yesod-core/Yesod/Core/Internal/Response.hs
+++ b/yesod-core/Yesod/Core/Internal/Response.hs
@@ -13,13 +13,11 @@ import qualified Data.ByteString.Char8        as S8
 import           Data.CaseInsensitive         (CI)
 import qualified Data.CaseInsensitive         as CI
 import           Network.Wai
-#if MIN_VERSION_wai(2, 0, 0)
 import           Data.Conduit                 (transPipe)
 import           Control.Monad.Trans.Resource (runInternalState, getInternalState, runResourceT, InternalState, closeInternalState)
 import           Control.Monad.Trans.Class    (lift)
 import           Network.Wai.Internal
 import           Control.Exception            (finally)
-#endif
 import           Prelude                      hiding (catch)
 import           Web.Cookie                   (renderSetCookie)
 import           Yesod.Core.Content
@@ -36,7 +34,6 @@ import           Data.Text.Encoding           (encodeUtf8)
 import           Data.Conduit                 (Flush (..), ($$))
 import qualified Data.Conduit.List            as CL
 
-#if MIN_VERSION_wai(3, 0, 0)
 yarToResponse :: YesodResponse
               -> (SessionMap -> IO [Header]) -- ^ save session
               -> YesodRequest
@@ -77,82 +74,6 @@ yarToResponse (YRPlain s' hs ct c newSess) saveSession yreq req is sendResponse
         | s' == defaultStatus = H.status200
         | otherwise = s'
 
-#else
-yarToResponse :: YesodResponse
-              -> (SessionMap -> IO [Header]) -- ^ save session
-              -> YesodRequest
-              -> Request
-#if MIN_VERSION_wai(2, 0, 0)
-              -> InternalState
-#endif
-              -> IO Response
-#if MIN_VERSION_wai(2, 0, 0)
-yarToResponse (YRWaiApp app) _ _ req _ = app req
-yarToResponse (YRWai a) _ _ _ is =
-    case a of
-        ResponseSource s hs w -> return $ ResponseSource s hs $ \f ->
-            w f `finally` closeInternalState is
-        ResponseBuilder{} -> do
-            closeInternalState is
-            return a
-        ResponseFile{} -> do
-            closeInternalState is
-            return a
-#if MIN_VERSION_wai(2, 1, 0)
-        -- Ignore the fallback provided, in case it refers to a ResourceT state
-        -- in a ResponseSource.
-        ResponseRaw raw _ -> return $ ResponseRaw
-            (\f -> raw f `finally` closeInternalState is)
-            (responseLBS H.status500 [("Content-Type", "text/plain")]
-                "yarToResponse: backend does not support raw responses")
-#endif
-#else
-yarToResponse (YRWai a) _ _ _ = return a
-#endif
-yarToResponse (YRPlain s' hs ct c newSess) saveSession yreq req
-#if MIN_VERSION_wai(2, 0, 0)
-  is
-#endif
-  = do
-    extraHeaders <- do
-        let nsToken = maybe
-                newSess
-                (\n -> Map.insert tokenKey (encodeUtf8 n) newSess)
-                (reqToken yreq)
-        sessionHeaders <- saveSession nsToken
-        return $ ("Content-Type", ct) : map headerToPair sessionHeaders
-    let finalHeaders = extraHeaders ++ map headerToPair hs
-        finalHeaders' len = ("Content-Length", S8.pack $ show len)
-                          : finalHeaders
-
-#if MIN_VERSION_wai(2, 0, 0)
-    let go (ContentBuilder b mlen) = do
-            let hs' = maybe finalHeaders finalHeaders' mlen
-            closeInternalState is
-            return $ ResponseBuilder s hs' b
-        go (ContentFile fp p) = do
-            closeInternalState is
-            return $ ResponseFile s finalHeaders fp p
-        go (ContentSource body) = return $ ResponseSource s finalHeaders $ \f ->
-            f (transPipe (flip runInternalState is) body) `finally`
-            closeInternalState is
-        go (ContentDontEvaluate c') = go c'
-    go c
-#else
-    let go (ContentBuilder b mlen) =
-            let hs' = maybe finalHeaders finalHeaders' mlen
-             in ResponseBuilder s hs' b
-        go (ContentFile fp p) = ResponseFile s finalHeaders fp p
-        go (ContentSource body) = ResponseSource s finalHeaders body
-        go (ContentDontEvaluate c') = go c'
-    return $ go c
-#endif
-  where
-    s
-        | s' == defaultStatus = H.status200
-        | otherwise = s'
-#endif
-
 -- | Indicates that the user provided no specific status code to be used, and
 -- therefore the default status code should be used. For normal responses, this
 -- would be a 200 response, whereas for error responses this would be an
diff --git a/yesod-core/Yesod/Core/Internal/Run.hs b/yesod-core/Yesod/Core/Internal/Run.hs
index 311f2088..6bb16587 100644
--- a/yesod-core/Yesod/Core/Internal/Run.hs
+++ b/yesod-core/Yesod/Core/Internal/Run.hs
@@ -34,13 +34,8 @@ import           Data.Text.Encoding.Error     (lenientDecode)
 import           Language.Haskell.TH.Syntax   (Loc, qLocation)
 import qualified Network.HTTP.Types           as H
 import           Network.Wai
-#if MIN_VERSION_wai(2, 0, 0)
 import           Network.Wai.Internal
-#endif
 import           Prelude                      hiding (catch)
-#if !MIN_VERSION_fast_logger(2, 0, 0)
-import           System.Log.FastLogger        (Logger)
-#endif
 import           System.Log.FastLogger        (LogStr, toLogStr)
 import           System.Random                (newStdGen)
 import           Yesod.Core.Content
@@ -220,22 +215,13 @@ runFakeHandler fakeSessionMap logger site handler = liftIO $ do
           , httpVersion    = H.http11
           , rawPathInfo    = "/runFakeHandler/pathInfo"
           , rawQueryString = ""
-#if MIN_VERSION_wai(2, 0, 0)
           , requestHeaderHost = Nothing
-#else
-          , serverName     = "runFakeHandler-serverName"
-          , serverPort     = 80
-#endif
           , requestHeaders = []
           , isSecure       = False
           , remoteHost     = error "runFakeHandler-remoteHost"
           , pathInfo       = ["runFakeHandler", "pathInfo"]
           , queryString    = []
-#if MIN_VERSION_wai(3, 0, 0)
           , requestBody    = return mempty
-#else
-          , requestBody    = mempty
-#endif
           , vault          = mempty
           , requestBodyLength = KnownLength 0
           }
@@ -258,13 +244,8 @@ yesodRunner :: (ToTypedContent res, Yesod site)
             -> YesodRunnerEnv site
             -> Maybe (Route site)
             -> Application
-#if MIN_VERSION_wai(3, 0, 0)
 yesodRunner handler' YesodRunnerEnv {..} route req sendResponse
   | Just maxLen <- mmaxLen, KnownLength len <- requestBodyLength req, maxLen < len = sendResponse tooLargeResponse
-#else
-yesodRunner handler' YesodRunnerEnv {..} route req
-  | Just maxLen <- mmaxLen, KnownLength len <- requestBodyLength req, maxLen < len = return tooLargeResponse
-#endif
   | otherwise = do
     let dontSaveSession _ = return []
     (session, saveSession) <- liftIO $ do
@@ -291,25 +272,11 @@ yesodRunner handler' YesodRunnerEnv {..} route req
         rhe = rheSafe
             { rheOnError = runHandler rheSafe . errorHandler
             }
-#if MIN_VERSION_wai(3, 0, 0)
 
     E.bracket createInternalState closeInternalState $ \is -> do
         yreq' <- yreq
         yar <- runInternalState (runHandler rhe handler yreq') is
         yarToResponse yar saveSession yreq' req is sendResponse
-
-#else
-
-#if MIN_VERSION_wai(2, 0, 0)
-    bracketOnError createInternalState closeInternalState $ \is -> do
-        yreq' <- yreq
-        yar <- runInternalState (runHandler rhe handler yreq') is
-        liftIO $ yarToResponse yar saveSession yreq' req is
-#else
-    yar <- runHandler rhe handler yreq
-    liftIO $ yarToResponse yar saveSession yreq req
-#endif
-#endif
   where
     mmaxLen = maximumContentLength yreSite route
     handler = yesodMiddleware handler'
diff --git a/yesod-core/Yesod/Core/Json.hs b/yesod-core/Yesod/Core/Json.hs
index 0f4185c5..b2669aa8 100644
--- a/yesod-core/Yesod/Core/Json.hs
+++ b/yesod-core/Yesod/Core/Json.hs
@@ -95,11 +95,7 @@ provideJson = provideRep . return . J.toJSON
 -- /Since: 0.3.0/
 parseJsonBody :: (MonadHandler m, J.FromJSON a) => m (J.Result a)
 parseJsonBody = do
-#if MIN_VERSION_resourcet(1,1,0)
     eValue <- rawRequestBody $$ runCatchC (sinkParser JP.value')
-#else
-    eValue <- runExceptionT $ rawRequestBody $$ sinkParser JP.value'
-#endif
     return $ case eValue of
         Left e -> J.Error $ show e
         Right value -> J.fromJSON value
diff --git a/yesod-core/Yesod/Core/Types.hs b/yesod-core/Yesod/Core/Types.hs
index 388dfe32..df208f27 100644
--- a/yesod-core/Yesod/Core/Types.hs
+++ b/yesod-core/Yesod/Core/Types.hs
@@ -5,7 +5,6 @@
 {-# LANGUAGE MultiParamTypeClasses      #-}
 {-# LANGUAGE TypeFamilies               #-}
 {-# LANGUAGE UndecidableInstances #-}
-{-# LANGUAGE CPP #-}
 module Yesod.Core.Types where
 
 import qualified Blaze.ByteString.Builder           as BBuilder
@@ -17,17 +16,12 @@ import           Control.Exception                  (Exception)
 import           Control.Monad                      (liftM, ap)
 import           Control.Monad.Base                 (MonadBase (liftBase))
 import           Control.Monad.Catch                (MonadCatch (..))
-#if MIN_VERSION_exceptions(0,6,0)
 import           Control.Monad.Catch                (MonadMask (..))
-#endif
 import           Control.Monad.IO.Class             (MonadIO (liftIO))
 import           Control.Monad.Logger               (LogLevel, LogSource,
                                                      MonadLogger (..))
 import           Control.Monad.Trans.Control        (MonadBaseControl (..))
 import           Control.Monad.Trans.Resource       (MonadResource (..), InternalState, runInternalState, MonadThrow (..), monadThrow, ResourceT)
-#if !MIN_VERSION_resourcet(1,1,0)
-import           Control.Monad.Trans.Resource       (MonadUnsafeIO (..))
-#endif
 import           Data.ByteString                    (ByteString)
 import qualified Data.ByteString.Lazy               as L
 import           Data.Conduit                       (Flush, Source)
@@ -52,12 +46,8 @@ import           Network.Wai                        (FilePart,
                                                      RequestBodyLength)
 import qualified Network.Wai                        as W
 import qualified Network.Wai.Parse                  as NWP
-#if MIN_VERSION_fast_logger(2, 0, 0)
 import           System.Log.FastLogger              (LogStr, LoggerSet, toLogStr, pushLogStr)
 import           Network.Wai.Logger                 (DateCacheGetter)
-#else
-import           System.Log.FastLogger              (LogStr, Logger, toLogStr)
-#endif
 import           Text.Blaze.Html                    (Html)
 import           Text.Hamlet                        (HtmlUrl)
 import           Text.Julius                        (JavascriptUrl)
@@ -68,9 +58,7 @@ import           Yesod.Routes.Class                 (RenderRoute (..), ParseRout
 import           Control.Monad.Reader               (MonadReader (..))
 import Prelude hiding (catch)
 import Control.DeepSeq (NFData (rnf))
-#if MIN_VERSION_conduit(1, 1, 0)
 import Data.Conduit.Lazy (MonadActive, monadActive)
-#endif
 
 -- Sessions
 type SessionMap = Map Text ByteString
@@ -146,11 +134,7 @@ data FileInfo = FileInfo
     }
 
 data FileUpload = FileUploadMemory !(NWP.BackEnd L.ByteString)
-#if MIN_VERSION_wai_extra(2, 0, 1)
                 | FileUploadDisk !(InternalState -> NWP.BackEnd FilePath)
-#else
-                | FileUploadDisk !(NWP.BackEnd FilePath)
-#endif
                 | FileUploadSource !(NWP.BackEnd (Source (ResourceT IO) ByteString))
 
 -- | How to determine the root of the application for constructing URLs.
@@ -423,14 +407,11 @@ instance Monad m => MonadReader site (WidgetT site m) where
 instance MonadTrans (WidgetT site) where
     lift = WidgetT . const . liftM (, mempty)
 instance MonadThrow m => MonadThrow (WidgetT site m) where
-#if MIN_VERSION_resourcet(1,1,0)
     throwM = lift . throwM
 
 instance MonadCatch m => MonadCatch (HandlerT site m) where
   catch (HandlerT m) c = HandlerT $ \r -> m r `catch` \e -> unHandlerT (c e) r
-#if MIN_VERSION_exceptions(0,6,0)
 instance MonadMask m => MonadMask (HandlerT site m) where
-#endif
   mask a = HandlerT $ \e -> mask $ \u -> unHandlerT (a $ q u) e
     where q u (HandlerT b) = HandlerT (u . b)
   uninterruptibleMask a =
@@ -438,35 +419,24 @@ instance MonadMask m => MonadMask (HandlerT site m) where
       where q u (HandlerT b) = HandlerT (u . b)
 instance MonadCatch m => MonadCatch (WidgetT site m) where
   catch (WidgetT m) c = WidgetT $ \r -> m r `catch` \e -> unWidgetT (c e) r
-#if MIN_VERSION_exceptions(0,6,0)
 instance MonadMask m => MonadMask (WidgetT site m) where
-#endif
   mask a = WidgetT $ \e -> mask $ \u -> unWidgetT (a $ q u) e
     where q u (WidgetT b) = WidgetT (u . b)
   uninterruptibleMask a =
     WidgetT $ \e -> uninterruptibleMask $ \u -> unWidgetT (a $ q u) e
       where q u (WidgetT b) = WidgetT (u . b)
-#else
-    monadThrow = lift . monadThrow
-#endif
 
-#if MIN_VERSION_resourcet(1,1,0)
 instance (Applicative m, MonadIO m, MonadBase IO m, MonadThrow m) => MonadResource (WidgetT site m) where
-#else
-instance (Applicative m, MonadIO m, MonadUnsafeIO m, MonadThrow m) => MonadResource (WidgetT site m) where
-#endif
     liftResourceT f = WidgetT $ \hd -> liftIO $ fmap (, 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)
 
-#if MIN_VERSION_conduit(1, 1, 0)
 instance MonadActive m => MonadActive (WidgetT site m) where
     monadActive = lift monadActive
 instance MonadActive m => MonadActive (HandlerT site m) where
     monadActive = lift monadActive
-#endif
 
 instance MonadTrans (HandlerT site) where
     lift = HandlerT . const
@@ -507,17 +477,9 @@ instance MonadBaseControl b m => MonadBaseControl b (HandlerT site m) where
     restoreM (StH base) = HandlerT $ const $ restoreM base
 
 instance MonadThrow m => MonadThrow (HandlerT site m) where
-#if MIN_VERSION_resourcet(1,1,0)
     throwM = lift . monadThrow
-#else
-    monadThrow = lift . monadThrow
-#endif
 
-#if MIN_VERSION_resourcet(1,1,0)
 instance (MonadIO m, MonadBase IO m, MonadThrow m) => MonadResource (HandlerT site m) where
-#else
-instance (MonadIO m, MonadUnsafeIO m, MonadThrow m) => MonadResource (HandlerT site m) where
-#endif
     liftResourceT f = HandlerT $ \hd -> liftIO $ runInternalState f (handlerResource hd)
 
 instance MonadIO m => MonadLogger (HandlerT site m) where
@@ -538,7 +500,6 @@ instance RenderRoute WaiSubsite where
 instance ParseRoute WaiSubsite where
     parseRoute (x, y) = Just $ WaiSubsiteRoute x y
 
-#if MIN_VERSION_fast_logger(2, 0, 0)
 data Logger = Logger
     { loggerSet :: !LoggerSet
     , loggerDate :: !DateCacheGetter
@@ -546,4 +507,3 @@ data Logger = Logger
 
 loggerPutStr :: Logger -> LogStr -> IO ()
 loggerPutStr (Logger ls _) = pushLogStr ls
-#endif
diff --git a/yesod-core/test/YesodCoreTest.hs b/yesod-core/test/YesodCoreTest.hs
index 703acda4..af4ed550 100644
--- a/yesod-core/test/YesodCoreTest.hs
+++ b/yesod-core/test/YesodCoreTest.hs
@@ -15,9 +15,7 @@ import qualified YesodCoreTest.Redirect as Redirect
 import qualified YesodCoreTest.JsLoader as JsLoader
 import qualified YesodCoreTest.RequestBodySize as RequestBodySize
 import qualified YesodCoreTest.Json as Json
-#if MIN_VERSION_wai(2, 1, 0)
 import qualified YesodCoreTest.RawResponse as RawResponse
-#endif
 import qualified YesodCoreTest.Streaming as Streaming
 import qualified YesodCoreTest.Reps as Reps
 import qualified YesodCoreTest.Auth as Auth
@@ -41,9 +39,7 @@ specs = do
       JsLoader.specs
       RequestBodySize.specs
       Json.specs
-#if MIN_VERSION_wai(2, 1, 0)
       RawResponse.specs
-#endif
       Streaming.specs
       Reps.specs
       Auth.specs
diff --git a/yesod-core/test/YesodCoreTest/CleanPath.hs b/yesod-core/test/YesodCoreTest/CleanPath.hs
index cbbd0cb5..ef100369 100644
--- a/yesod-core/test/YesodCoreTest/CleanPath.hs
+++ b/yesod-core/test/YesodCoreTest/CleanPath.hs
@@ -33,11 +33,7 @@ instance ParseRoute Subsite where
     parseRoute (x, _) = Just $ SubsiteRoute x
 
 instance YesodSubDispatch Subsite master where
-#if MIN_VERSION_wai(3, 0, 0)
     yesodSubDispatch _ req f = f $ responseLBS
-#else
-    yesodSubDispatch _ req = return $ responseLBS
-#endif
         status200
         [ ("Content-Type", "SUBSITE")
         ] $ L8.pack $ show (pathInfo req)
diff --git a/yesod-core/test/YesodCoreTest/WaiSubsite.hs b/yesod-core/test/YesodCoreTest/WaiSubsite.hs
index b16d0f65..b319b9e3 100644
--- a/yesod-core/test/YesodCoreTest/WaiSubsite.hs
+++ b/yesod-core/test/YesodCoreTest/WaiSubsite.hs
@@ -6,11 +6,7 @@ import Yesod.Core
 import qualified Network.HTTP.Types as H
 
 myApp :: Application
-#if MIN_VERSION_wai(3, 0, 0)
 myApp _ f = f $ responseLBS H.status200 [("Content-type", "text/plain")] "WAI"
-#else
-myApp _ = return $ responseLBS H.status200 [("Content-type", "text/plain")] "WAI"
-#endif
 
 getApp :: a -> WaiSubsite
 getApp _ = WaiSubsite myApp
diff --git a/yesod-core/yesod-core.cabal b/yesod-core/yesod-core.cabal
index dae69489..44855f59 100644
--- a/yesod-core/yesod-core.cabal
+++ b/yesod-core/yesod-core.cabal
@@ -49,7 +49,7 @@ library
                    , directory             >= 1
                    , vector                >= 0.9      && < 0.11
                    , aeson                 >= 0.5
-                   , fast-logger           >= 0.2
+                   , fast-logger           >= 2.1
                    , wai-logger            >= 0.2
                    , monad-logger          >= 0.3.1    && < 0.4
                    , conduit               >= 1.2
@@ -62,7 +62,7 @@ library
                    , warp                  >= 1.3.8
                    , unix-compat
                    , conduit-extra
-                   , exceptions
+                   , exceptions            >= 0.6
                    , deepseq
 
     exposed-modules: Yesod.Core
diff --git a/yesod-form/Yesod/Form/Fields.hs b/yesod-form/Yesod/Form/Fields.hs
index c6091a99..4b7ef2fd 100644
--- a/yesod-form/Yesod/Form/Fields.hs
+++ b/yesod-form/Yesod/Form/Fields.hs
@@ -75,11 +75,7 @@ import Data.Maybe (listToMaybe, fromMaybe)
 import qualified Blaze.ByteString.Builder.Html.Utf8 as B
 import Blaze.ByteString.Builder (writeByteString, toLazyByteString)
 import Blaze.ByteString.Builder.Internal.Write (fromWriteList)
-#if MIN_VERSION_persistent(2, 0, 0)
 import Database.Persist (PersistEntityBackend)
-#else
-import Database.Persist (PersistMonadBackend, PersistEntityBackend)
-#endif
 
 import Text.Blaze.Html.Renderer.String (renderHtml)
 import qualified Data.ByteString as S
@@ -559,21 +555,12 @@ optionsPairs opts = do
 optionsEnum :: (MonadHandler m, Show a, Enum a, Bounded a) => m (OptionList a)
 optionsEnum = optionsPairs $ map (\x -> (pack $ show x, x)) [minBound..maxBound]
 
-#if MIN_VERSION_persistent(2, 0, 0)
 optionsPersist :: ( YesodPersist site, PersistEntity a
                   , PersistQuery (PersistEntityBackend a)
                   , PathPiece (Key a)
                   , RenderMessage site msg
                   , YesodPersistBackend site ~ PersistEntityBackend a
                   )
-#else
-optionsPersist :: ( YesodPersist site, PersistEntity a
-                  , PersistQuery (YesodPersistBackend site (HandlerT site IO))
-                  , PathPiece (Key a)
-                  , PersistEntityBackend a ~ PersistMonadBackend (YesodPersistBackend site (HandlerT site IO))
-                  , RenderMessage site msg
-                  )
-#endif
                => [Filter a]
                -> [SelectOpt a]
                -> (a -> msg)
@@ -591,7 +578,6 @@ optionsPersist filts ords toDisplay = fmap mkOptionList $ do
 -- the entire @Entity@.
 --
 -- Since 1.3.2
-#if MIN_VERSION_persistent(2, 0, 0)
 optionsPersistKey
   :: (YesodPersist site
      , PersistEntity a
@@ -600,15 +586,6 @@ optionsPersistKey
      , RenderMessage site msg
      , YesodPersistBackend site ~ PersistEntityBackend a
      )
-#else
-optionsPersistKey
-  :: (YesodPersist site
-     , PersistEntity a
-     , PersistQuery (YesodPersistBackend site (HandlerT site IO))
-     , PathPiece (Key a)
-     , RenderMessage site msg
-     , PersistEntityBackend a ~ PersistMonadBackend (YesodDB site))
-#endif
   => [Filter a]
   -> [SelectOpt a]
   -> (a -> msg)
diff --git a/yesod-persistent/Yesod/Persist/Core.hs b/yesod-persistent/Yesod/Persist/Core.hs
index 7f9b6b05..b40cd72a 100644
--- a/yesod-persistent/Yesod/Persist/Core.hs
+++ b/yesod-persistent/Yesod/Persist/Core.hs
@@ -20,9 +20,6 @@ module Yesod.Persist.Core
     ) where
 
 import Database.Persist
-#if !MIN_VERSION_persistent(2, 0, 0)
-import Database.Persist.Sql (SqlPersistT, unSqlPersistT)
-#endif
 import Control.Monad.Trans.Reader (ReaderT, runReaderT)
 
 import Yesod.Core
@@ -34,24 +31,13 @@ import Control.Exception (throwIO)
 import Yesod.Core.Types (HandlerContents (HCError))
 import qualified Database.Persist.Sql as SQL
 
-#if MIN_VERSION_persistent(2, 0, 0)
 unSqlPersistT :: a -> a
 unSqlPersistT = id
-#endif
 
-#if MIN_VERSION_persistent(2, 0, 0)
 type YesodDB site = ReaderT (YesodPersistBackend site) (HandlerT site IO)
-#else
-type YesodDB site = YesodPersistBackend site (HandlerT site IO)
-#endif
 
-#if MIN_VERSION_persistent(2, 0, 0)
 class Monad (YesodDB site) => YesodPersist site where
     type YesodPersistBackend site
-#else
-class Monad (YesodPersistBackend site (HandlerT site IO)) => YesodPersist site where
-    type YesodPersistBackend site :: (* -> *) -> * -> *
-#endif
     runDB :: YesodDB site a -> HandlerT site IO a
 
 -- | Helper for creating 'runDB'.
@@ -94,11 +80,7 @@ newtype DBRunner site = DBRunner
 -- | Helper for implementing 'getDBRunner'.
 --
 -- Since 1.2.0
-#if MIN_VERSION_persistent(2, 0, 0)
 defaultGetDBRunner :: YesodPersistBackend site ~ SQL.SqlBackend
-#else
-defaultGetDBRunner :: YesodPersistBackend site ~ SqlPersistT
-#endif
                    => (site -> Pool SQL.Connection)
                    -> HandlerT site IO (DBRunner site, HandlerT site IO ())
 defaultGetDBRunner getPool = do
@@ -142,20 +124,9 @@ respondSourceDB :: YesodPersistRunner site
 respondSourceDB ctype = respondSource ctype . runDBSource
 
 -- | Get the given entity by ID, or return a 404 not found if it doesn't exist.
-#if MIN_VERSION_persistent(2, 0, 0)
 get404 :: (MonadIO m, PersistStore (PersistEntityBackend val), PersistEntity val)
        => Key val
        -> ReaderT (PersistEntityBackend val) m val
-#else
-get404 :: ( PersistStore (t m)
-          , PersistEntity val
-          , Monad (t m)
-          , m ~ HandlerT site IO
-          , MonadTrans t
-          , PersistMonadBackend (t m) ~ PersistEntityBackend val
-          )
-       => Key val -> t m val
-#endif
 get404 key = do
     mres <- get key
     case mres of
@@ -164,20 +135,9 @@ get404 key = do
 
 -- | Get the given entity by unique key, or return a 404 not found if it doesn't
 --   exist.
-#if MIN_VERSION_persistent(2, 0, 0)
 getBy404 :: (PersistUnique (PersistEntityBackend val), PersistEntity val, MonadIO m)
          => Unique val
          -> ReaderT (PersistEntityBackend val) m (Entity val)
-#else
-getBy404 :: ( PersistUnique (t m)
-            , PersistEntity val
-            , m ~ HandlerT site IO
-            , Monad (t m)
-            , MonadTrans t
-            , PersistEntityBackend val ~ PersistMonadBackend (t m)
-            )
-         => Unique val -> t m (Entity val)
-#endif
 getBy404 key = do
     mres <- getBy key
     case mres of
@@ -188,11 +148,3 @@ getBy404 key = do
 -- GHC 7.4.2 that leads to segfaults. This is a workaround.
 notFound' :: MonadIO m => m a
 notFound' = liftIO $ throwIO $ HCError NotFound
-
-#if !MIN_VERSION_persistent(2, 0, 0)
-instance MonadHandler m => MonadHandler (SqlPersistT m) where
-    type HandlerSite (SqlPersistT m) = HandlerSite m
-    liftHandlerT = lift . liftHandlerT
-instance MonadWidget m => MonadWidget (SqlPersistT m) where
-    liftWidgetT = lift . liftWidgetT
-#endif
diff --git a/yesod-persistent/test/Yesod/PersistSpec.hs b/yesod-persistent/test/Yesod/PersistSpec.hs
index c1d5eb59..c8b365aa 100644
--- a/yesod-persistent/test/Yesod/PersistSpec.hs
+++ b/yesod-persistent/test/Yesod/PersistSpec.hs
@@ -29,11 +29,7 @@ mkYesod "App" [parseRoutes|
 
 instance Yesod App
 instance YesodPersist App where
-#if MIN_VERSION_persistent(2, 0, 0)
     type YesodPersistBackend App = SqlBackend
-#else
-    type YesodPersistBackend App = SqlPersistT
-#endif
     runDB = defaultRunDB appConfig appPool
 instance YesodPersistRunner App where
     getDBRunner = defaultGetDBRunner appPool
diff --git a/yesod-static/Yesod/EmbeddedStatic.hs b/yesod-static/Yesod/EmbeddedStatic.hs
index e5d2a14c..48634f3e 100644
--- a/yesod-static/Yesod/EmbeddedStatic.hs
+++ b/yesod-static/Yesod/EmbeddedStatic.hs
@@ -90,11 +90,7 @@ instance Yesod master => YesodSubDispatch EmbeddedStatic (HandlerT master IO) wh
             resp = case pathInfo req of
                             ("res":_) -> stApp site req
                             ("widget":_) -> staticApp (widgetSettings site) req
-#if MIN_VERSION_wai(3,0,0)
                             _ -> ($ responseLBS status404 [] "Not Found")
-#else
-                            _ -> return $ responseLBS status404 [] "Not Found"
-#endif
 
 -- | Create the haskell variable for the link to the entry
 mkRoute :: ComputedEntry -> Q [Dec]
diff --git a/yesod-static/Yesod/EmbeddedStatic/Internal.hs b/yesod-static/Yesod/EmbeddedStatic/Internal.hs
index 640c4e32..a2e92ab0 100644
--- a/yesod-static/Yesod/EmbeddedStatic/Internal.hs
+++ b/yesod-static/Yesod/EmbeddedStatic/Internal.hs
@@ -107,11 +107,7 @@ prodEmbed e = do
     return $ ComputedEntry (ebHaskellName e) st link
 
 toApp :: (Request -> IO Response) -> Application
-#if MIN_VERSION_wai(3, 0, 0)
 toApp f req g = f req >>= g
-#else
-toApp = id
-#endif
 
 tryExtraDevelFiles :: [[T.Text] -> IO (Maybe (MimeType, BL.ByteString))] -> Application
 tryExtraDevelFiles = toApp . tryExtraDevelFiles'
@@ -133,19 +129,11 @@ tryExtraDevelFiles' (f:fs) r = do
 
 -- | Helper to create the development application at runtime
 develApp :: StaticSettings -> [[T.Text] -> IO (Maybe (MimeType, BL.ByteString))] -> Application
-#if MIN_VERSION_wai(3, 0, 0)
 develApp settings extra req sendResponse = do
     staticApp settings {ssMaxAge = NoMaxAge} req $ \resp ->
         if statusCode (responseStatus resp) == 404
             then tryExtraDevelFiles extra req sendResponse
             else sendResponse resp
-#else
-develApp settings extra req = do
-    resp <- staticApp settings {ssMaxAge = NoMaxAge} req
-    if statusCode (responseStatus resp) == 404
-        then tryExtraDevelFiles extra req
-        else return resp
-#endif
 
 -- | The type of 'addStaticContent'
 type AddStaticContent site = T.Text -> T.Text -> BL.ByteString
diff --git a/yesod-websockets/Yesod/WebSockets.hs b/yesod-websockets/Yesod/WebSockets.hs
index 58146f9b..3df66e81 100644
--- a/yesod-websockets/Yesod/WebSockets.hs
+++ b/yesod-websockets/Yesod/WebSockets.hs
@@ -47,11 +47,7 @@ webSockets :: (Y.MonadBaseControl IO m, Y.MonadHandler m) => WebSocketsT m () ->
 webSockets inner = do
     req <- Y.waiRequest
     when (WaiWS.isWebSocketsReq req) $
-#if MIN_VERSION_wai(3, 0, 0)
         Y.sendRawResponseNoConduit
-#else
-        Y.sendRawResponse
-#endif
           $ \src sink -> control $ \runInIO -> WaiWS.runWebSockets
             WS.defaultConnectionOptions
             (WaiWS.getRequestHead req)
diff --git a/yesod/Yesod/Default/Main.hs b/yesod/Yesod/Default/Main.hs
index 565ed353..44e094e4 100644
--- a/yesod/Yesod/Default/Main.hs
+++ b/yesod/Yesod/Default/Main.hs
@@ -76,12 +76,7 @@ defaultMainLog load getApp = do
             (toLogStr $ "Exception from Warp: " ++ show e)
         } app
   where
-    shouldLog' =
-#if MIN_VERSION_warp(2,1,3)
-        Warp.defaultShouldDisplayException
-#else
-        const True
-#endif
+    shouldLog' = Warp.defaultShouldDisplayException
 
 -- | Run your application continously, listening for SIGINT and exiting
 --   when received