diff --git a/.travis.yml b/.travis.yml
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,30 +1,60 @@
 language: haskell
 
 env:
-  - GHCVER=7.4.2
-  - GHCVER=7.6.3
-  - GHCVER=7.8.2
-  - GHCVER=head
+  global:
+    # OAUTH_CONSUMER_KEY
+    - secure: "U3hh6wJf87tdZmwLtPyMQ0ci39ouKvTm/JCi0CCz2jaPvWZR+4Tt7aYV5WYqzjSmgfBOqKpXTpwFBcvvWRty8rI1b8OtrlljC1zUcgf/hsz3hfPtv+GKW/ldYnqg7znyeAdxWEF1a4JszKgOJaGMdX7zSpFewgwEq7T4jAlebLA="
+    # OAUTH_CONSUMER_SECRET
+    - secure: "I4BGd16zNQE3WjnwgdT7OM5sIIMtT9DMFPNdnWJPcgYndDovnFAUDoTomaGo0Wue4h64vGWl26f2Nm04i2upJXxkzFFtU5Az6cwUjzkOve1yqrkkyPFTXC8MLQYX3Zz8scQ8h1IJCn0Luu5HsHsool6IFZpiUovLZbDXmY44yH4="
+    # OAUTH_ACCESS_TOKEN
+    - secure: "dW2pYRplxJ7HmJEo3lMgLlzfdOylBvWiV4PJt1j4GMDPJBOu3RM0h3zNkkxDoS9D0wWRkBEH0iN2Bh08v2z7sJtF3f/kgLvPlOy5mNSYcozwMdHJRlJEcXaGULHbZ4p79lVIOdTAhY2WU2QdP7PEv0BiqqVcysnfK0TGkTa+KEc="
+    # OAUTH_ACCESS_SECRET
+    - secure: "I5hzi7sONDn8KJAhmkroHsGNJ2zUxYq2iGamTV9lgMUDH0bwpMx+guzfZr+fGesdlUphM0t+ZCh9YH8BoVJsjZ/db9u/lotg78DKp1QwhrWnISqWj6TIfXrSLPkBwY+xFtxl6Ihsjyl+ileiK5sb0C9mC+zXidgBqEM73miAokY="
+  matrix:
+    - GHCVER=7.4.2
+    - GHCVER=7.6.3
+    - GHCVER=7.8.2 USE_COVERALLS=1 CABAL_FLAGS="-frun-integrated-test"
+    - GHCVER=head
 
 matrix:
   allow_failures:
     - env: GHCVER=head
 
 before_install:
-  - travis_retry sudo add-apt-repository -y ppa:hvr/ghc
-  - travis_retry sudo apt-get update
-  - travis_retry sudo apt-get install cabal-install-1.18 ghc-$GHCVER
-  - export PATH=/opt/ghc/$GHCVER/bin:/opt/cabal/1.18/bin:$PATH
+  - |
+    if [ $GHCVER = `ghc --numeric-version` ]; then
+      echo "use system ghc: `which ghc` `ghc --numeric-version`"
+    else
+      travis_retry sudo add-apt-repository -y ppa:hvr/ghc
+      travis_retry sudo apt-get update
+      travis_retry sudo apt-get install  -y --force-yes cabal-install-1.18 ghc-$GHCVER
+      export PATH=/opt/ghc/$GHCVER/bin:/opt/cabal/1.18/bin:$PATH
+      echo "use ppa:hvr/ghc: `which ghc` `ghc --numeric-version`"
+    fi
 
 install:
   - export PATH=$HOME/.cabal/bin:$PATH
   - which cabal
-  - cabal update
+  - travis_retry cabal update
   - cabal install happy --constraint="transformers < 0.4"
   - cabal install --only-dependencies --enable-tests
+  - "[ -n \"$USE_COVERALLS\" ] && travis_retry cabal install hpc-coveralls || true"
   - ghc-pkg list
 
 script:
-  - cabal configure --enable-tests
+  - |
+    if [ -n "$USE_COVERALLS" ]; then
+      cabal configure --enable-tests --enable-library-coverage $CABAL_FLAGS
+    else
+      cabal configure --enable-tests $CABAL_FLAGS
+    fi
   - cabal build
-  - cabal test --show-details=always
+  - |
+    if [ -n "$USE_COVERALLS" ]; then
+      run-cabal-test --show-details=always
+    else
+      cabal test --show-details=always
+    fi
+
+after_script:
+  - "[ -n \"$USE_COVERALLS\" ] && hpc-coveralls spec_main || true"
diff --git a/Web/Twitter/Conduit/Api.hs b/Web/Twitter/Conduit/Api.hs
--- a/Web/Twitter/Conduit/Api.hs
+++ b/Web/Twitter/Conduit/Api.hs
@@ -47,6 +47,7 @@
        , FriendsList
        , friendsList
        -- , followersList
+       -- , friendshipsLookup
 
        -- * Users
        -- , accountSettings
@@ -72,7 +73,11 @@
        -- , usersContributors
        -- , accuntRemoveProfileBanner
        -- , accuntUpdateProfileBanner
-       -- , accuntProfileBanner
+       -- , usersProfileBanner
+       -- , mutesUsersCreate
+       -- , mutesUsersDestroy
+       -- , mutesUsersIds
+       -- , mutesUsersList
 
        -- * Suggested Users
        -- , usersSuggestionsSlug
@@ -87,16 +92,39 @@
        , favoritesCreate
 
        -- * Lists
+       -- , listsList
        -- , listsStatuses
+       -- , listsMembersDestroy
        -- , listsMemberships
        -- , listsSubscribers
+       -- , listsSubscribersCreate
        -- , listsSubscribersShow
+       -- , listsSubscribersDestroy
+       -- , listsSubscribersCreateAll
        -- , listsMembersShow
        , ListsMembers
        , listsMembers
-       -- , lists
+       -- , listsMembersCreate
+       -- , listsDestroy
+       -- , listsUpdate
+       -- , listsCreate
        -- , listsShow
        -- , listsSubscriptions
+       -- , listsMembersDestroyAll
+       -- , listsOwnerships
+
+       -- * Saved Searches
+       -- savedSearchesList
+       -- savedSearchesShowId
+       -- savedSearchesCreate
+       -- savedSearchesDestroyId
+
+       -- * Places & Geo
+       -- geoIdPlaceId
+       -- geoReverseGeocode
+       -- geoSearch
+       -- geoSimilarPlaces
+       -- geoPlace
        ) where
 
 import Web.Twitter.Types
diff --git a/Web/Twitter/Conduit/Base.hs b/Web/Twitter/Conduit/Base.hs
--- a/Web/Twitter/Conduit/Base.hs
+++ b/Web/Twitter/Conduit/Base.hs
@@ -3,12 +3,7 @@
 {-# LANGUAGE CPP #-}
 {-# LANGUAGE TemplateHaskell #-}
 {-# LANGUAGE QuasiQuotes #-}
-#if __GLASGOW_HASKELL__ >= 704
 {-# LANGUAGE ConstraintKinds #-}
-#else
-{-# LANGUAGE FlexibleInstances #-}
-{-# LANGUAGE UndecidableInstances #-}
-#endif
 
 module Web.Twitter.Conduit.Base
        ( api
@@ -47,19 +42,15 @@
 import qualified Data.ByteString.Char8 as S8
 import Control.Monad.IO.Class
 import Control.Monad.Trans.Class (lift)
+import Control.Monad.Trans.Resource (MonadResource, MonadThrow, monadThrow)
 import Text.Shakespeare.Text
 import Control.Monad.Logger
 import Control.Lens
 import Unsafe.Coerce
 
-#if __GLASGOW_HASKELL__ >= 704
-type TwitterBaseM m = ( C.MonadResource m
+type TwitterBaseM m = ( MonadResource m
                       , MonadLogger m
                       )
-#else
-class (C.MonadResource m, MonadLogger m) => TwitterBaseM m
-instance (C.MonadResource m, MonadLoger m) => TwitterBaseM m
-#endif
 
 makeRequest :: MonadIO m
             => HT.Method -- ^ HTTP request method (GET or POST)
@@ -191,7 +182,7 @@
         CL.sourceList $ contents res
         loop $ nextCursor res
 
-sinkJSON :: ( C.MonadThrow m
+sinkJSON :: ( MonadThrow m
             , MonadLogger m
             ) => C.Consumer ByteString m Value
 sinkJSON = do
@@ -200,13 +191,13 @@
     return js
 
 sinkFromJSON :: ( FromJSON a
-                , C.MonadThrow m
+                , MonadThrow m
                 , MonadLogger m
                 ) => C.Consumer ByteString m a
 sinkFromJSON = do
     v <- sinkJSON
     case fromJSON v of
-        Error err -> lift $ C.monadThrow $ TwitterError err
+        Error err -> lift $ monadThrow $ TwitterError err
         Success r -> return r
 
 showBS :: Show a => a -> ByteString
diff --git a/Web/Twitter/Conduit/Cursor.hs b/Web/Twitter/Conduit/Cursor.hs
--- a/Web/Twitter/Conduit/Cursor.hs
+++ b/Web/Twitter/Conduit/Cursor.hs
@@ -53,7 +53,7 @@
     { previousCursor :: Integer
     , nextCursor :: Integer
     , contents :: [wrapped]
-    }
+    } deriving Show
 
 instance (FromJSON wrapped, CursorKey c) =>
          FromJSON (WithCursor c wrapped) where
diff --git a/Web/Twitter/Conduit/Monad.hs b/Web/Twitter/Conduit/Monad.hs
--- a/Web/Twitter/Conduit/Monad.hs
+++ b/Web/Twitter/Conduit/Monad.hs
@@ -101,7 +101,7 @@
 getManager :: Monad m => TW m Manager
 getManager = asks twManager
 
-signOAuthTW :: MonadUnsafeIO m
+signOAuthTW :: MonadIO m
             => Request
             -> TW m Request
 signOAuthTW req = do
diff --git a/sample/oauth_callback.hs b/sample/oauth_callback.hs
--- a/sample/oauth_callback.hs
+++ b/sample/oauth_callback.hs
@@ -9,7 +9,7 @@
 
 import Web.Scotty
 import qualified Network.HTTP.Types as HT
-import Web.Twitter.Conduit hiding (text)
+import Web.Twitter.Conduit hiding (text, lookup)
 import Web.Authenticate.OAuth (OAuth(..), Credential(..))
 import qualified Web.Authenticate.OAuth as OA
 import qualified Network.HTTP.Conduit as HTTP
diff --git a/sample/oauth_pin.hs b/sample/oauth_pin.hs
--- a/sample/oauth_pin.hs
+++ b/sample/oauth_pin.hs
@@ -8,7 +8,7 @@
 
 module Main where
 
-import Web.Twitter.Conduit
+import Web.Twitter.Conduit hiding (lookup)
 import Web.Authenticate.OAuth as OA
 import Network.HTTP.Conduit
 import qualified Data.Conduit as C
diff --git a/tests/ApiSpec.hs b/tests/ApiSpec.hs
new file mode 100644
--- /dev/null
+++ b/tests/ApiSpec.hs
@@ -0,0 +1,59 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE CPP #-}
+
+module ApiSpec where
+
+import Data.Conduit
+import qualified Data.Conduit.List as CL
+import Web.Twitter.Conduit (call, sourceWithCursor)
+import Web.Twitter.Conduit.Api
+import Web.Twitter.Conduit.Cursor (contents)
+import qualified Web.Twitter.Conduit.Parameters as Param
+import Web.Twitter.Types.Lens
+import Control.Lens
+import TestUtils
+
+import Test.Hspec
+
+import System.IO.Unsafe
+
+self :: User
+self = unsafePerformIO . run . call $ accountVerifyCredentials
+
+spec :: Spec
+spec = do
+    unit
+#ifdef RUN_INTEGRATED_TEST
+    integrated
+#endif
+
+unit :: Spec
+unit = return ()
+
+integrated :: Spec
+integrated = do
+    describe "friendsIds" $ do
+        it "returns a cursored collection of users IDs" $ do
+            res <- run . call $ friendsIds (Param.ScreenNameParam "thimura")
+            length (contents res) `shouldSatisfy` (> 0)
+
+        it "iterate with sourceWithCursor" $ do
+            friends <- run $ do
+                let src = sourceWithCursor $ friendsIds (Param.ScreenNameParam "thimura")
+                src $$ CL.consume
+            length friends `shouldSatisfy` (>= 0)
+
+    describe "listsMembers" $ do
+        it "returns a cursored collection of the member of specified list" $ do
+            res <- run . call $ listsMembers (Param.ListNameParam "thimura/haskell")
+            length (contents res) `shouldSatisfy` (>= 0)
+
+        it "should raise error when specified list does not exists" $ do
+            let action = run . call $ listsMembers (Param.ListNameParam "thimura/haskell_ne")
+            action `shouldThrow` anyException
+
+        it "iterate with sourceWithCursor" $ do
+            members <- run $ do
+                let src = sourceWithCursor $ listsMembers (Param.ListNameParam "thimura/haskell")
+                src $$ CL.consume
+            members ^.. traversed . userScreenName `shouldContain` ["Hackage"]
diff --git a/tests/Spec.hs b/tests/Spec.hs
new file mode 100644
--- /dev/null
+++ b/tests/Spec.hs
@@ -0,0 +1,1 @@
+{-# OPTIONS_GHC -F -pgmF hspec-discover -optF --no-main #-}
diff --git a/tests/StatusSpec.hs b/tests/StatusSpec.hs
new file mode 100644
--- /dev/null
+++ b/tests/StatusSpec.hs
@@ -0,0 +1,96 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE CPP #-}
+
+module StatusSpec where
+
+import Data.Conduit
+import qualified Data.Conduit.List as CL
+import Web.Twitter.Conduit (call, accountVerifyCredentials, sourceWithMaxId)
+import Web.Twitter.Conduit.Status as Status
+import qualified Web.Twitter.Conduit.Parameters as Param
+import Web.Twitter.Types.Lens
+import Control.Lens
+import TestUtils
+
+import Test.Hspec
+
+import System.IO.Unsafe
+
+self :: User
+self = unsafePerformIO . run . call $ accountVerifyCredentials
+
+spec :: Spec
+spec = do
+    unit
+#ifdef RUN_INTEGRATED_TEST
+    integrated
+#endif
+
+unit :: Spec
+unit = return ()
+
+integrated :: Spec
+integrated = do
+    describe "mentionsTimeline" $ do
+        it "returns the 20 most resent mentions for user" $ do
+            res <- run $ call mentionsTimeline
+            length res `shouldSatisfy` (> 0)
+            let mentionsScreenName = res ^.. traversed . statusEntities . _Just . enUserMentions . traversed . entityBody . userEntityUserScreenName
+            mentionsScreenName `shouldSatisfy` allOf folded (== (self ^. userScreenName))
+            length mentionsScreenName `shouldSatisfy` (== length res)
+
+    describe "userTimeline" $ do
+        it "returns the 20 most recent tweets posted by the user indicated by ScreenNameParam" $ do
+            res <- run . call $ userTimeline (Param.ScreenNameParam "thimura")
+            length res `shouldSatisfy` (== 20)
+            res `shouldSatisfy` (allOf folded (^. statusUser . userScreenName . to (== "thimura")))
+        it "returns the recent tweets which include RTs when specified include_rts option" $ do
+            res <- run . call
+                   $ userTimeline (Param.ScreenNameParam "thimura")
+                   & Param.count ?~ 100 & Param.includeRts ?~ True
+            res `shouldSatisfy` (anyOf (folded . statusRetweet . _Just . statusUser . userScreenName) (/= "thimura"))
+        it "iterate with sourceWithMaxId" $ do
+            tl <- run $ do
+                let src = sourceWithMaxId $ userTimeline (Param.ScreenNameParam "thimura") & Param.count ?~ 200
+                src $$ CL.isolate 600 =$ CL.consume
+            length tl `shouldSatisfy` (== 600)
+
+            let ids = tl ^.. traversed . statusId
+            zip ids (tail ids) `shouldSatisfy` all (\(a, b) -> a > b)
+
+    describe "homeTimeline" $ do
+        it "returns the most recent tweets in home timeline" $ do
+            res <- run $ call homeTimeline
+            length res `shouldSatisfy` (> 0)
+
+    describe "retweetsOfMe" $ do
+        let response = unsafePerformIO . run . call $ retweetsOfMe
+        it "returns the most recent tweets authored by the authenticating user" $ do
+             let screenNames = response ^.. traversed . statusUser . userScreenName
+             screenNames `shouldSatisfy` allOf folded (== (self ^. userScreenName))
+             length screenNames `shouldSatisfy` (== length response)
+        it "returns the most recent tweets that have been retweeted by other" $ do
+            response `shouldSatisfy` allOf (traversed . statusRetweetCount . _Just) (> 0)
+
+    describe "showId" $ do
+        it "works for the known tweets" $ do
+            res <- run . call $ showId 477833886768959488
+            res ^. statusId `shouldBe` 477833886768959488
+            res ^. statusText `shouldBe` "真紅かわいいはアレセイア"
+            res ^. statusCreatedAt `shouldBe` "Sat Jun 14 15:24:10 +0000 2014"
+            res ^. statusUser . userScreenName `shouldBe` "thimura"
+
+    describe "update & destroyId" $ do
+        it "posts new tweet and destroy it" $ do
+            res1 <- run . call $ update "おまえの明日が、今日よりもずっと、楽しい事で溢れているようにと、祈っているよ"
+            res1 ^. statusUser . userScreenName `shouldBe` self ^. userScreenName
+
+            res2 <- run . call $ destroyId (res1 ^. statusId)
+            res2 ^. statusId `shouldBe` res1 ^. statusId
+
+    describe "lookup" $ do
+        it "works for the known tweets" $ do
+            res <- run . call $ Status.lookup [438691466345340928, 477757405942411265]
+            length res `shouldSatisfy` (== 2)
+            (res !! 0) ^. statusId `shouldBe` 438691466345340928
+            (res !! 1) ^. statusId `shouldBe` 477757405942411265
diff --git a/tests/TestUtils.hs b/tests/TestUtils.hs
new file mode 100644
--- /dev/null
+++ b/tests/TestUtils.hs
@@ -0,0 +1,68 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE ConstraintKinds #-}
+{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE CPP #-}
+
+module TestUtils (runTwitterFromEnv, run) where
+
+import Web.Twitter.Conduit
+
+import Web.Authenticate.OAuth as OA
+import qualified Network.URI as URI
+import Network.HTTP.Conduit
+import qualified Data.Map as M
+import qualified Data.ByteString.Char8 as S8
+import qualified Data.CaseInsensitive as CI
+import Control.Applicative
+import Control.Monad.IO.Class
+import Control.Monad.Base
+import Control.Monad.Trans.Resource
+import System.Environment
+import Control.Monad.Logger
+import Control.Lens
+
+getOAuthTokens :: IO (OAuth, Credential)
+getOAuthTokens = do
+    consumerKey <- getEnv' "OAUTH_CONSUMER_KEY"
+    consumerSecret <- getEnv' "OAUTH_CONSUMER_SECRET"
+    accessToken <- getEnv' "OAUTH_ACCESS_TOKEN"
+    accessSecret <- getEnv' "OAUTH_ACCESS_SECRET"
+    let oauth = twitterOAuth
+            { oauthConsumerKey = consumerKey
+            , oauthConsumerSecret = consumerSecret
+            }
+        cred = Credential
+            [ ("oauth_token", accessToken)
+            , ("oauth_token_secret", accessSecret)
+            ]
+    return (oauth, cred)
+  where
+    getEnv' = (S8.pack <$>) . getEnv
+
+getProxyEnv :: IO (Maybe Proxy)
+getProxyEnv = do
+    env <- M.fromList . over (mapped . _1) CI.mk <$> getEnvironment
+    let u = M.lookup "https_proxy" env <|>
+            M.lookup "http_proxy" env <|>
+            M.lookup "proxy" env >>= URI.parseURI >>= URI.uriAuthority
+    return $ Proxy <$> (S8.pack . URI.uriRegName <$> u) <*> (parsePort . URI.uriPort <$> u)
+  where
+    parsePort :: String -> Int
+    parsePort []       = 8080
+    parsePort (':':xs) = read xs
+    parsePort xs       = error $ "port number parse failed " ++ xs
+
+runTwitterFromEnv :: (MonadIO m, MonadBaseControl IO m) => TW (ResourceT m) a -> m a
+runTwitterFromEnv task = do
+    pr <- liftBase getProxyEnv
+    (oa, cred) <- liftBase getOAuthTokens
+    let env = (setCredential oa cred def) { twProxy = pr }
+    runTW env task
+
+#ifdef USE_DEBUG_OUTPUT
+run :: (MonadIO m, MonadBaseControl IO m) => TW (ResourceT (LoggingT m)) a -> m a
+run = runStderrLoggingT . runTwitterFromEnv
+#else
+run :: (MonadIO m, MonadBaseControl IO m) => TW (ResourceT (NoLoggingT m)) a -> m a
+run = runNoLoggingT . runTwitterFromEnv
+#endif
diff --git a/tests/spec_main.hs b/tests/spec_main.hs
new file mode 100644
--- /dev/null
+++ b/tests/spec_main.hs
@@ -0,0 +1,4 @@
+import Spec
+import Test.Hspec
+
+main = hspec spec
diff --git a/twitter-conduit.cabal b/twitter-conduit.cabal
--- a/twitter-conduit.cabal
+++ b/twitter-conduit.cabal
@@ -1,5 +1,5 @@
 name:              twitter-conduit
-version:           0.0.3
+version:           0.0.4
 license:           BSD3
 license-file:      LICENSE
 author:            HATTORI Hiroki, Hideyuki Tanaka, Takahiro HIMURA
@@ -35,29 +35,33 @@
   description: build samples
   default: False
 
+flag use-debug-output
+  description: use debug output when running testsuites
+  default: False
+
+flag run-integrated-test
+  description: use debug output when running testsuites
+  default: False
+
 library
   ghc-options: -Wall
 
   build-depends:
-      base >= 4 && < 5
+      base >= 4.5 && < 5
     , transformers >= 0.2.2
-    , transformers-base
     , template-haskell
-    , lifted-base >= 0.1
-    , monad-control >= 0.3
     , lens >= 4.0
     , authenticate-oauth >= 1.3
-    , resourcet >= 0.4.3 && < 0.5
-    , conduit >= 1.0 && < 1.1
-    , failure >= 0.2
+    , resourcet >= 1.0
+    , conduit >= 1.1
+    , conduit-extra >= 1.1
     , monad-logger
     , shakespeare >= 2.0
     , http-types
-    , http-conduit >= 2.0 && < 2.1
+    , http-conduit >= 2.0 && < 2.2
     , http-client >= 0.3
     , aeson >= 0.7
     , attoparsec >= 0.10
-    , attoparsec-conduit >= 1.0
     , data-default >= 0.3
     , bytestring >= 0.9
     , text >= 0.11
@@ -101,6 +105,49 @@
     , directory
     , doctest
 
+test-suite spec_main
+  type: exitcode-stdio-1.0
+  main-is: spec_main.hs
+  hs-source-dirs: tests, .
+  if flag(use-debug-output)
+    CPP-Options: -DUSE_DEBUG_OUTPUT
+
+  if flag(run-integrated-test)
+    CPP-Options: -DRUN_INTEGRATED_TEST
+
+  build-depends:
+      base >= 4.5 && < 5
+    , template-haskell
+    , transformers-base
+    , transformers
+    , monad-control
+    , lens
+    , bytestring
+    , time
+    , text
+    , aeson
+    , attoparsec >= 0.10
+    , shakespeare
+    , data-default
+    , resourcet
+    , conduit
+    , conduit-extra >= 1.1
+    , http-types
+    , http-conduit
+    , http-client
+    , monad-logger
+    , authenticate-oauth
+    , case-insensitive
+    , network
+    , containers
+    , hspec
+    , twitter-types
+  other-modules:
+    Spec
+    ApiSpec
+    StatusSpec
+    TestUtils
+
 executable simple
   main-is: simple.hs
   hs-source-dirs: sample/
@@ -109,7 +156,7 @@
     buildable: False
   else
     build-depends:
-        base >= 4.0 && < 5
+        base >= 4.5 && < 5
       , transformers-base
       , transformers
       , monad-control
@@ -132,7 +179,7 @@
     buildable: False
   else
     build-depends:
-        base >= 4.0 && < 5
+        base >= 4.5 && < 5
       , containers
       , transformers-base
       , transformers
@@ -162,7 +209,7 @@
     buildable: False
   else
     build-depends:
-        base >= 4.0 && < 5
+        base >= 4.5 && < 5
       , containers
       , transformers-base
       , transformers
@@ -185,7 +232,7 @@
     buildable: False
   else
     build-depends:
-        base >= 4.0 && < 5
+        base >= 4.5 && < 5
       , containers
       , transformers-base
       , transformers