diff --git a/DataVersion.cabal b/DataVersion.cabal
--- a/DataVersion.cabal
+++ b/DataVersion.cabal
@@ -1,18 +1,16 @@
 cabal-version: 1.12
 
--- This file has been generated from package.yaml by hpack version 0.31.2.
+-- This file has been generated from package.yaml by hpack version 0.35.0.
 --
 -- see: https://github.com/sol/hpack
---
--- hash: 21c291662b767b5c5923f5b8dd4a621d30578be2dae431d97c7dd06383954ec5
 
 name:           DataVersion
-version:        0.1.0.0
+version:        0.1.0.1
 synopsis:       Type safe data migrations
-description:    Please see the README on GitHub at <https://github.com/agentultra/DataMigration#readme>
+description:    Please see the README on GitHub at <https://github.com/agentultra/DataVersion#readme>
 category:       Data
-homepage:       https://github.com/agentultra/DataMigration#readme
-bug-reports:    https://github.com/agentultra/DataMigration/issues
+homepage:       https://github.com/agentultra/DataVersion#readme
+bug-reports:    https://github.com/agentultra/DataVersion/issues
 author:         Sandy Maguire, James King
 maintainer:     james@agentultra.com
 copyright:      2019 Sandy Maguire, James King
@@ -25,7 +23,7 @@
 
 source-repository head
   type: git
-  location: https://github.com/agentultra/DataMigration
+  location: https://github.com/agentultra/DataVersion
 
 library
   exposed-modules:
@@ -35,11 +33,27 @@
       Paths_DataVersion
   hs-source-dirs:
       src
-  default-extensions: DataKinds TypeFamilies QuantifiedConstraints DeriveGeneric MultiParamTypeClasses FlexibleContexts FlexibleInstances PolyKinds AllowAmbiguousTypes DuplicateRecordFields FunctionalDependencies GeneralizedNewtypeDeriving ScopedTypeVariables TypeApplications TypeOperators UndecidableInstances
+  default-extensions:
+      DataKinds
+      TypeFamilies
+      QuantifiedConstraints
+      DeriveGeneric
+      MultiParamTypeClasses
+      FlexibleContexts
+      FlexibleInstances
+      PolyKinds
+      AllowAmbiguousTypes
+      DuplicateRecordFields
+      FunctionalDependencies
+      GeneralizedNewtypeDeriving
+      ScopedTypeVariables
+      TypeApplications
+      TypeOperators
+      UndecidableInstances
   build-depends:
       base >=4.7 && <5
-    , generic-lens >=1.1.0.0 && <2
-    , microlens >=0.4.10 && <2
+    , generic-lens
+    , microlens
   default-language: Haskell2010
 
 test-suite DataVersion-test
@@ -49,7 +63,23 @@
       Paths_DataVersion
   hs-source-dirs:
       test
-  default-extensions: DataKinds TypeFamilies QuantifiedConstraints DeriveGeneric MultiParamTypeClasses FlexibleContexts FlexibleInstances PolyKinds AllowAmbiguousTypes DuplicateRecordFields FunctionalDependencies GeneralizedNewtypeDeriving ScopedTypeVariables TypeApplications TypeOperators UndecidableInstances
+  default-extensions:
+      DataKinds
+      TypeFamilies
+      QuantifiedConstraints
+      DeriveGeneric
+      MultiParamTypeClasses
+      FlexibleContexts
+      FlexibleInstances
+      PolyKinds
+      AllowAmbiguousTypes
+      DuplicateRecordFields
+      FunctionalDependencies
+      GeneralizedNewtypeDeriving
+      ScopedTypeVariables
+      TypeApplications
+      TypeOperators
+      UndecidableInstances
   ghc-options: -threaded -rtsopts -with-rtsopts=-N
   build-depends:
       DataVersion
diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -1,5 +1,7 @@
 # DataMigration
 
+[![Hackage](https://img.shields.io/hackage/v/DataVersion.svg?logo=haskell&label=DataVersion)](https://hackage.haskell.org/package/DataVersion)
+
 Type safe data migrations.
 
 All you need to do is create a type family to index your record and
@@ -8,6 +10,44 @@
 
 Migrations are type-safe and the library uses generics to remove as
 much boiler-plate as possible.
+
+## Examples
+
+```haskell
+data family Foo (version :: Nat)
+
+newtype MyString = MyString { unMyString :: String }
+   deriving (IsString, Show, Eq)
+
+data instance Foo 0
+  = FooV0
+    { _fooId :: Int
+    , _fooName :: String
+    }
+  deriving (Generic, Show, Eq)
+
+data instance Foo 1
+  = FooV1
+  { _fooId        :: Int
+  , _fooName      :: MyString
+  , _fooHonorific :: String
+  }
+  deriving (Generic, Show, Eq)
+
+instance Transform Foo 0 where
+  up   v = genericUp   v (const "esquire") (const MyString)
+  down v = genericDown v (const unMyString)
+
+
+spjV0 :: Foo 0
+spjV0 = FooV0 1 "Simon PJ"
+
+
+spjV1 :: Foo 1
+spjV1 = up spjV0
+
+-- spjV1 = FooV1 1 (MyString "Simon PJ") "esquire"
+```
 
 ## Future Considerations
 
diff --git a/src/Data/Migration/Internal.hs b/src/Data/Migration/Internal.hs
--- a/src/Data/Migration/Internal.hs
+++ b/src/Data/Migration/Internal.hs
@@ -88,7 +88,7 @@
   type Function ('Change name ti to ': ts) src dst  = (src -> ti -> to) -> Function ts src dst
   gTransform dst src mk_to = gTransform @ts (dst & field' @name .~ mk_to src (src ^. field' @name)) src
 
-class GUndefinedFields (o :: * -> *) where
+class GUndefinedFields (o :: Type -> Type) where
   gUndefinedFields :: o x
 
 instance GUndefinedFields o => GUndefinedFields (M1 _3 _4 o) where