diff --git a/CHANGES.md b/CHANGES.md
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,6 +1,11 @@
 Changes
 =======
 
+Version 0.2.0.1
+---------------
+
+Fix compatibility with older ghcs
+
 Version 0.2
 -----------
 
diff --git a/Data/Generics/Traversable.hs b/Data/Generics/Traversable.hs
--- a/Data/Generics/Traversable.hs
+++ b/Data/Generics/Traversable.hs
@@ -46,6 +46,7 @@
 import Data.Monoid
 import Data.Functor.Identity
 import Data.Functor.Constant
+import Data.Proxy.Fork
 
 import Data.Generics.Traversable.Core
 import Data.Generics.Traversable.Instances ()
@@ -97,8 +98,6 @@
   -> r -> a -> r
 gfoldl' f z0 xs = gfoldr f' id xs z0
   where f' x k z = k $! f z x
-
-data Proxy (c :: * -> Constraint) = Proxy
 
 -- | Apply a transformation everywhere in bottom-up manner
 everywhere
diff --git a/Data/Generics/Traversable/Zipper.hs b/Data/Generics/Traversable/Zipper.hs
--- a/Data/Generics/Traversable/Zipper.hs
+++ b/Data/Generics/Traversable/Zipper.hs
@@ -93,8 +93,8 @@
 import Control.Monad ((<=<), MonadPlus, mzero, mplus, liftM)
 import Data.Maybe (fromJust)
 import Data.Generics.Traversable
-import Data.Typeable
-import Data.Proxy
+import Data.Typeable (Typeable, cast)
+import Data.Proxy.Fork
 import GHC.Exts (Constraint)
 import Control.Applicative
 
diff --git a/Data/Proxy/Fork.hs b/Data/Proxy/Fork.hs
new file mode 100644
--- /dev/null
+++ b/Data/Proxy/Fork.hs
@@ -0,0 +1,8 @@
+{-# LANGUAGE ConstraintKinds, KindSignatures, PolyKinds #-}
+-- | In @tagged@, PolyKinds are enabled only starting with 7.6. Hence we
+-- have our own Proxy.
+module Data.Proxy.Fork where
+
+import GHC.Exts (Constraint)
+
+data Proxy (c :: * -> Constraint) = Proxy
diff --git a/traverse-with-class.cabal b/traverse-with-class.cabal
--- a/traverse-with-class.cabal
+++ b/traverse-with-class.cabal
@@ -2,7 +2,7 @@
 -- documentation, see http://haskell.org/cabal/users-guide/
 
 name:                traverse-with-class
-version:             0.2
+version:             0.2.0.1
 synopsis:            Generic applicative traversals
 description:         This is a generic programming library in the spirit of
                      \"Scrap your boilerplate with class\", but with several
@@ -30,6 +30,7 @@
   other-modules:
                        Data.Generics.Traversable.Core
                        Data.Generics.Traversable.Instances
+                       Data.Proxy.Fork
   build-depends:       base == 4.*, transformers, template-haskell
   default-language:    Haskell2010
   other-extensions:    TemplateHaskell