diff --git a/Control/Monad/Classes/ReadState.hs b/Control/Monad/Classes/ReadState.hs
--- a/Control/Monad/Classes/ReadState.hs
+++ b/Control/Monad/Classes/ReadState.hs
@@ -6,7 +6,6 @@
 import Control.Monad.Classes.State
 import Control.Monad.Trans.Identity
 import Control.Monad.Trans.Class
-import Control.Applicative
 import Control.Monad.Base
 import Control.Monad.Trans.Control
 import Data.Peano
@@ -39,7 +38,7 @@
   liftBase = lift . liftBase
 
 instance MonadTransControl (ReadStateT x) where
-  type StT (ReadStateT s) a = StT IdentityT a
+  type StT (ReadStateT x) a = StT IdentityT a
   liftWith = defaultLiftWith ReadStateT (\(ReadStateT a) -> a)
   restoreT = defaultRestoreT ReadStateT
 
diff --git a/Control/Monad/Classes/Writer.hs b/Control/Monad/Classes/Writer.hs
--- a/Control/Monad/Classes/Writer.hs
+++ b/Control/Monad/Classes/Writer.hs
@@ -12,7 +12,6 @@
 import Control.Monad.Classes.Core
 import Control.Monad.Classes.Effects
 import Control.Monad.Classes.Proxied
-import Data.Monoid
 import Data.Peano
 
 type instance CanDo (WL.WriterT w m) eff = WriterCanDo w eff
diff --git a/Control/Monad/Classes/Zoom.hs b/Control/Monad/Classes/Zoom.hs
--- a/Control/Monad/Classes/Zoom.hs
+++ b/Control/Monad/Classes/Zoom.hs
@@ -13,7 +13,6 @@
 import Control.Monad.Classes.Writer
 import Control.Monad.Classes.Proxied
 import Data.Functor.Identity
-import Data.Monoid
 import Data.Peano (Peano (..))
 
 newtype ZoomT big small m a = ZoomT (Proxied (VLLens big small) m a)
diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-[![Build Status](https://travis-ci.org/feuerbach/monad-classes.svg?branch=master)](https://travis-ci.org/feuerbach/monad-classes)
+[![Build Status](https://travis-ci.org/strake/monad-classes.hs.svg?branch=master)](https://travis-ci.org/strake/monad-classes.hs)
 
 See [this series of articles][1] for the detailed description and motivation.
 
diff --git a/monad-classes.cabal b/monad-classes.cabal
--- a/monad-classes.cabal
+++ b/monad-classes.cabal
@@ -1,5 +1,5 @@
 name:                monad-classes
-version:             0.3.2.0
+version:             0.3.2.1
 synopsis:            more flexible mtl
 -- description:
 homepage:            https://github.com/strake/monad-classes.hs
@@ -13,6 +13,10 @@
 extra-source-files:
   README.md
 cabal-version:       >=1.10
+tested-with:         GHC >=7.8.2 && <7.9,
+                     GHC ==7.10.*,
+                     GHC ==7.12.*,
+                     GHC ==8.0.*
 
 library
   exposed-modules:
@@ -63,7 +67,7 @@
 Test-suite test
   Default-language:
     Haskell2010
-  Extensions:
+  Default-extensions:
     FlexibleContexts
   Type:
     exitcode-stdio-1.0
diff --git a/tests/test.hs b/tests/test.hs
--- a/tests/test.hs
+++ b/tests/test.hs
@@ -48,6 +48,7 @@
   , liftConduitTest
   , mapWriterTest
   , readStateTest
+  , polymorphicTests
   ]
 
 readerTests = testGroup "Reader Tests"
@@ -151,7 +152,7 @@
   => Proxy# eff
   -> C.ConduitM i o effM r
   -> C.ConduitM i o m    r
-liftConduit _ = hoist (liftN (proxy# :: Proxy# n))
+liftConduit _ = C.transPipe (liftN (proxy# :: Proxy# n))
 
 liftConduitTest = testCase "lift conduit" $
   (let
@@ -163,7 +164,7 @@
       C.await >>=
         maybe (return ()) (\x -> do lift $ tell [x::Int]; sink)
    in
-    W.execWriter $ hoist (liftN (proxy# :: Proxy# (Succ Zero))) src C.$$ sink
+    W.execWriter $ C.transPipe (liftN (proxy# :: Proxy# (Succ Zero))) src C.$$ sink
   ) @?= [1,2]
   {-
 
@@ -189,3 +190,15 @@
     a2 = runReadState (Proxy :: Proxy Char) a1
 
   run (evalStateStrict 'w' a2) @?= 'w'
+
+polymorphicTests = testGroup "Polymorphic monadic values"
+  [ testCase "MonadReader WriterT" $ do
+      run (runReader 'c' (W.runWriterT polyReader1)) @?= ('c', ())
+  , testCase "MonadReader ReaderT" $ do
+      run (runReader 'c' (runReader False polyReader2)) @?= 'c'
+  ]
+  where
+    polyReader1 :: MonadReader Char m => W.WriterT () m Char
+    polyReader1 = ask
+    polyReader2 :: MonadReader Char m => R.ReaderT Bool m Char
+    polyReader2 = ask