diff --git a/Control/Comonad/Trans/Discont/Lazy.hs b/Control/Comonad/Trans/Discont/Lazy.hs
--- a/Control/Comonad/Trans/Discont/Lazy.hs
+++ b/Control/Comonad/Trans/Discont/Lazy.hs
@@ -27,6 +27,7 @@
   , runDiscontT
   -- * Combinators
   , callCV
+  , label
   ) where
 
 import Data.Functor.Identity
@@ -46,15 +47,18 @@
 runDiscontT :: DiscontT s w a -> (w s -> a, w s)
 runDiscontT ~(DiscontT f s) = (f, s)
 
-instance Functor w => Functor (DiscontT s w) where
+instance Functor (DiscontT s w) where
   fmap g ~(DiscontT f ws) = DiscontT (g . f) ws
 
-instance Comonad w => Comonad (DiscontT s w) where
+instance Comonad (DiscontT s w) where
   extract ~(DiscontT f ws) = f ws
   duplicate ~(DiscontT f ws) = DiscontT (DiscontT f) ws
 
 instance ComonadTrans (DiscontT s) where
   lower ~(DiscontT f s) = extend f s
+
+label :: Comonad w => DiscontT s w a -> s 
+label ~(DiscontT _ ws) = extract ws
 
 callCV :: DiscontT s w (DiscontT s w (DiscontT s w a -> a) -> b) -> b
 callCV ~(DiscontT k s) = k s (DiscontT (\s' ~(DiscontT k' _) -> k' s') s)
diff --git a/Control/Comonad/Trans/Discont/Strict.hs b/Control/Comonad/Trans/Discont/Strict.hs
--- a/Control/Comonad/Trans/Discont/Strict.hs
+++ b/Control/Comonad/Trans/Discont/Strict.hs
@@ -27,6 +27,7 @@
   , runDiscontT
   -- * Combinators
   , callCV
+  , label
   ) where
 
 import Data.Functor.Identity
@@ -46,15 +47,19 @@
 runDiscontT :: DiscontT s w a -> (w s -> a, w s)
 runDiscontT (DiscontT f s) = (f, s)
 
-instance Functor w => Functor (DiscontT s w) where
+instance Functor (DiscontT s w) where
   fmap g (DiscontT f ws) = DiscontT (g . f) ws
 
-instance Comonad w => Comonad (DiscontT s w) where
+instance Comonad (DiscontT s w) where
   extract (DiscontT f ws) = f ws
   duplicate (DiscontT f ws) = DiscontT (DiscontT f) ws
+  extend g (DiscontT f ws) = DiscontT (g . DiscontT f) ws
 
 instance ComonadTrans (DiscontT s) where
   lower (DiscontT f s) = extend f s
 
 callCV :: DiscontT s w (DiscontT s w (DiscontT s w a -> a) -> b) -> b
 callCV (DiscontT k s) = k s (DiscontT (\s' (DiscontT k' _) -> k' s') s)
+
+label :: Comonad w => DiscontT s w a -> s
+label (DiscontT _ ws) = extract ws
diff --git a/Control/Comonad/Trans/Env/Lazy.hs b/Control/Comonad/Trans/Env/Lazy.hs
--- a/Control/Comonad/Trans/Env/Lazy.hs
+++ b/Control/Comonad/Trans/Env/Lazy.hs
@@ -31,6 +31,8 @@
 import Control.Comonad
 import Control.Comonad.Trans.Class
 import Control.Comonad.Hoist.Class
+import Control.Comonad.Apply
+import Data.Functor.Apply
 import Data.Functor.Identity
 import Data.Monoid
 
diff --git a/Control/Comonad/Trans/Env/Strict.hs b/Control/Comonad/Trans/Env/Strict.hs
--- a/Control/Comonad/Trans/Env/Strict.hs
+++ b/Control/Comonad/Trans/Env/Strict.hs
@@ -29,8 +29,10 @@
   ) where
 
 import Control.Comonad
+import Control.Comonad.Apply
 import Control.Comonad.Trans.Class
 import Control.Comonad.Hoist.Class
+import Data.Functor.Apply
 import Data.Functor.Identity
 import Data.Monoid
 
diff --git a/Control/Comonad/Trans/Stream.hs b/Control/Comonad/Trans/Stream.hs
--- a/Control/Comonad/Trans/Stream.hs
+++ b/Control/Comonad/Trans/Stream.hs
@@ -30,8 +30,10 @@
 
 import Control.Applicative
 import Control.Comonad
+import Control.Comonad.Apply
 import Control.Comonad.Hoist.Class
 import Control.Comonad.Trans.Class
+import Data.Functor.Apply
 import Data.Functor.Identity
 import Data.Foldable
 import Data.Monoid
diff --git a/Control/Comonad/Trans/Traced.hs b/Control/Comonad/Trans/Traced.hs
--- a/Control/Comonad/Trans/Traced.hs
+++ b/Control/Comonad/Trans/Traced.hs
@@ -27,9 +27,11 @@
   ) where
 
 import Control.Comonad
+import Control.Comonad.Apply
 import Control.Comonad.Hoist.Class
 import Control.Comonad.Trans.Class
 import Data.Functor
+import Data.Functor.Apply
 import Data.Functor.Identity
 import Data.Monoid
 
diff --git a/comonad-transformers.cabal b/comonad-transformers.cabal
--- a/comonad-transformers.cabal
+++ b/comonad-transformers.cabal
@@ -1,6 +1,6 @@
 name:          comonad-transformers
 category:      Control, Comonads
-version:       0.5.0
+version:       0.6.0
 license:       BSD3
 cabal-version: >= 1.2
 license-file:  LICENSE
@@ -18,7 +18,8 @@
   build-depends: 
     base >= 4 && < 4.4,
     array >= 0.3.0.1 && < 0.4,
-    comonad >= 0.5 && < 0.6,
+    comonad >= 0.6 && < 0.7,
+    functor-apply >= 0.6 && < 0.7,
     transformers >= 0.2.0 && <= 0.3
 
   exposed-modules: