CofreeT's Show instance does not work

[exergasia]

It spins endlessly and produces an infinite string of repeating "CofreeT (". It's a one line fix but I added a test for it anyway:

diff --git a/free.cabal b/free.cabal
index 86df40e..30ff931 100644
--- a/free.cabal
+++ b/free.cabal
@@ -95,3 +95,12 @@ library
     Control.Monad.Trans.Iter

   ghc-options: -Wall
+
+test-suite CofreeTShowRead
+  hs-source-dirs: test/
+  default-language:   Haskell2010
+  type:           exitcode-stdio-1.0
+  main-is:        CofreeTShowRead.hs
+  build-depends:
+    base                 == 4.*,
+    free
diff --git a/src/Control/Comonad/Trans/Cofree.hs b/src/Control/Comonad/Trans/Cofree.hs
index bdf8ce7..20e6ad3 100644
--- a/src/Control/Comonad/Trans/Cofree.hs
+++ b/src/Control/Comonad/Trans/Cofree.hs
@@ -139,7 +139,7 @@ instance (Functor f, Comonad w) => ComonadCofree f (CofreeT f w) where
   unwrap = tailF . extract . runCofreeT

 instance Show (w (CofreeF f a (CofreeT f w a))) => Show (CofreeT f w a) where
-  showsPrec d w = showParen (d > 10) $
+  showsPrec d (CofreeT w) = showParen (d > 10) $
     showString "CofreeT " . showsPrec 11 w

 instance Read (w (CofreeF f a (CofreeT f w a))) => Read (CofreeT f w a) where
diff --git a/test/CofreeTShowRead.hs b/test/CofreeTShowRead.hs
new file mode 100644
index 0000000..dc471b7
--- /dev/null
+++ b/test/CofreeTShowRead.hs
@@ -0,0 +1,10 @@
+import Control.Comonad.Trans.Cofree
+import Control.Monad
+import System.Exit
+
+main = do
+  let x :: CofreeT Maybe [] Bool
+      x = CofreeT [True :< Nothing]
+      x' :: CofreeT Maybe [] Bool
+      x' = read . show $ x
+  when (x /= x') exitFailure