diff --git a/CHANGELOG.markdown b/CHANGELOG.markdown
--- a/CHANGELOG.markdown
+++ b/CHANGELOG.markdown
@@ -1,3 +1,7 @@
+4.0.1
+-----
+* Increased lower bound on `contravariant` to match the actual requirement.
+
 4.0
 ---
 * Merged the contents of `representable-functors`.
diff --git a/adjunctions.cabal b/adjunctions.cabal
--- a/adjunctions.cabal
+++ b/adjunctions.cabal
@@ -1,6 +1,6 @@
 name:          adjunctions
 category:      Data Structures, Adjunctions
-version:       4.0
+version:       4.0.1
 license:       BSD3
 cabal-version: >= 1.6
 license-file:  LICENSE
@@ -44,7 +44,7 @@
     base          >= 4       && < 5,
     comonad       >= 4       && < 5,
     containers    >= 0.3     && < 0.6,
-    contravariant >= 0.2.0.1 && < 1,
+    contravariant >= 0.4.1   && < 1,
     distributive  >= 0.4     && < 1,
     free          >= 4       && < 5,
     mtl           >= 2.0.1   && < 2.2,
diff --git a/src/Control/Comonad/Trans/Adjoint.hs b/src/Control/Comonad/Trans/Adjoint.hs
--- a/src/Control/Comonad/Trans/Adjoint.hs
+++ b/src/Control/Comonad/Trans/Adjoint.hs
@@ -50,12 +50,12 @@
 instance (Adjunction f g, Comonad w) => Comonad (AdjointT f g w) where
   extend f (AdjointT m) = AdjointT $ fmap (extend $ leftAdjunct (f . AdjointT)) m
   extract = rightAdjunct extract . runAdjointT
-  
+
 {-
 instance (Adjunction f g, Monad m) => Applicative (AdjointT f g m) where
   pure = AdjointT . leftAdjunct return
   (<*>) = ap
 -}
-    
+
 instance (Adjunction f g, Distributive g) => ComonadTrans (AdjointT f g) where
-  lower = counit . fmap distribute . runAdjointT 
+  lower = counit . fmap distribute . runAdjointT
diff --git a/src/Control/Monad/Trans/Conts.hs b/src/Control/Monad/Trans/Conts.hs
--- a/src/Control/Monad/Trans/Conts.hs
+++ b/src/Control/Monad/Trans/Conts.hs
@@ -18,7 +18,7 @@
 ----------------------------------------------------------------------------
 
 module Control.Monad.Trans.Conts
-  ( 
+  (
   -- * Continuation passing style
     Cont
   , cont
@@ -63,7 +63,7 @@
 
 instance Comonad w => Apply (ContsT r w m) where
   (<.>) = ap
-  
+
 instance Comonad w => Applicative (ContsT r w m) where
   pure x = ContsT $ \f -> extract f x
   (<*>) = ap
@@ -77,8 +77,8 @@
 
 {-
 callCCs :: Comonad w => (w (a -> ContsT r w m b) -> ContsT r w m a) -> ContsT r w m a
-callCCs f = 
+callCCs f =
 -}
 
 instance Comonad w => MonadTrans (ContsT r w) where
-  lift m = ContsT $ extract . fmap (m >>=) 
+  lift m = ContsT $ extract . fmap (m >>=)