diff --git a/product-isomorphic.cabal b/product-isomorphic.cabal
--- a/product-isomorphic.cabal
+++ b/product-isomorphic.cabal
@@ -1,5 +1,5 @@
 name:                product-isomorphic
-version:             0.0.2.0
+version:             0.0.3.0
 synopsis:            Weaken applicative functor on products
 description:         Weaken applicative functor which allows only product
                      construction. Product constructions and deconstructions
@@ -26,6 +26,7 @@
                      Data.Functor.ProductIsomorphic.Class
                      Data.Functor.ProductIsomorphic.Instances
                      Data.Functor.ProductIsomorphic.TupleInstances
+                     Data.Functor.ProductIsomorphic.GenericInstances
                      Data.Functor.ProductIsomorphic.Unsafe
                      Data.Functor.ProductIsomorphic
 
diff --git a/src/Data/Functor/ProductIsomorphic.hs b/src/Data/Functor/ProductIsomorphic.hs
--- a/src/Data/Functor/ProductIsomorphic.hs
+++ b/src/Data/Functor/ProductIsomorphic.hs
@@ -8,13 +8,14 @@
 -- Portability : unknown
 --
 -- This is the integrated interface module for product restricted functors.
-module Data.Functor.ProductIsomorphic
-       ( module Data.Functor.ProductIsomorphic.Unsafe
-       , module Data.Functor.ProductIsomorphic.Class
-       , module Data.Functor.ProductIsomorphic.Instances
-       ) where
+module Data.Functor.ProductIsomorphic (
+  module Data.Functor.ProductIsomorphic.Unsafe,
+  module Data.Functor.ProductIsomorphic.Class,
+  module Data.Functor.ProductIsomorphic.Instances,
+  ) where
 
 import Data.Functor.ProductIsomorphic.Unsafe (ProductConstructor)
 import Data.Functor.ProductIsomorphic.Class
 import Data.Functor.ProductIsomorphic.Instances
 import Data.Functor.ProductIsomorphic.TupleInstances ()
+import Data.Functor.ProductIsomorphic.GenericInstances ()
diff --git a/src/Data/Functor/ProductIsomorphic/GenericInstances.hs b/src/Data/Functor/ProductIsomorphic/GenericInstances.hs
new file mode 100644
--- /dev/null
+++ b/src/Data/Functor/ProductIsomorphic/GenericInstances.hs
@@ -0,0 +1,46 @@
+{-# OPTIONS_GHC -fno-warn-orphans #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE TypeOperators #-}
+
+-- |
+-- Module      : Data.Functor.ProductIsomorphic.GenericInstances
+-- Copyright   : 2017 Kei Hibino
+-- License     : BSD3
+--
+-- Maintainer  : ex8k.hibino@gmail.com
+-- Stability   : experimental
+-- Portability : unknown
+--
+-- This module defines instances for constructors used in generic-programming.
+module Data.Functor.ProductIsomorphic.GenericInstances () where
+
+import GHC.Generics
+  (U1 (U1), K1 (K1), M1 (M1), (:*:) ((:*:)), )
+-- import GHC.Generics (Generic, Rep, from, to, )
+
+import Data.Functor.ProductIsomorphic.Unsafe (ProductConstructor (..))
+
+
+instance ProductConstructor (U1 p) where
+  productConstructor = U1
+  {-# INLINEABLE productConstructor #-}
+
+instance ProductConstructor (c -> K1 i c p) where
+  productConstructor = K1
+  {-# INLINEABLE productConstructor #-}
+
+instance ProductConstructor (f p -> M1 i c f p) where
+  productConstructor = M1
+  {-# INLINEABLE productConstructor #-}
+
+instance ProductConstructor (f x -> g x -> (f :*: g) x) where
+  productConstructor = (:*:)
+  {-# INLINEABLE productConstructor #-}
+
+{- -- why compile error?
+instance Generic a => ProductConstructor (a -> Rep a x) where
+  productConstructor = from
+
+instance Generic a => ProductConstructor (Rep a x -> a) where
+  productConstructor = to
+ -}
diff --git a/src/Data/Functor/ProductIsomorphic/Instances.hs b/src/Data/Functor/ProductIsomorphic/Instances.hs
--- a/src/Data/Functor/ProductIsomorphic/Instances.hs
+++ b/src/Data/Functor/ProductIsomorphic/Instances.hs
@@ -12,10 +12,10 @@
 --
 -- This module defines functor instances morphed functions
 -- are restricted to products.
-module Data.Functor.ProductIsomorphic.Instances
-       ( WrappedFunctor (..)
-       , WrappedAlter (..)
-       ) where
+module Data.Functor.ProductIsomorphic.Instances (
+  WrappedFunctor (..),
+  WrappedAlter (..),
+  ) where
 
 import Data.Monoid (Monoid, mempty, (<>))
 import Control.Applicative
diff --git a/src/Data/Functor/ProductIsomorphic/TH/Internal.hs b/src/Data/Functor/ProductIsomorphic/TH/Internal.hs
--- a/src/Data/Functor/ProductIsomorphic/TH/Internal.hs
+++ b/src/Data/Functor/ProductIsomorphic/TH/Internal.hs
@@ -27,22 +27,23 @@
 import Data.Functor.ProductIsomorphic.Unsafe (ProductConstructor (..))
 
 
-recordInfo' :: Info -> Maybe ((TypeQ, ExpQ), (Maybe [Name], [TypeQ]))
+recordInfo' :: Info -> Maybe (((TypeQ, [Name]), ExpQ), (Maybe [Name], [TypeQ]))
 recordInfo' =  d  where
   d (TyConI tcon) = do
     (_cxt, tcn, bs, _mk, [r], _ds) <- unDataD tcon
+    let vns = map getTV bs
     case r of
-      NormalC dcn ts   -> Just ((buildT tcn bs, conE dcn), (Nothing, [return t | (_, t) <- ts]))
-      RecC    dcn vts  -> Just ((buildT tcn bs, conE dcn), (Just ns, ts))
+      NormalC dcn ts   -> Just (((buildT tcn vns, vns), conE dcn), (Nothing, [return t | (_, t) <- ts]))
+      RecC    dcn vts  -> Just (((buildT tcn vns, vns), conE dcn), (Just ns, ts))
         where (ns, ts) = unzip [(n, return t) | (n, _, t) <- vts]
       _                -> Nothing
   d _                  =  Nothing
   getTV (PlainTV n)    =  n
   getTV (KindedTV n _) =  n
-  buildT tcn bs = foldl' appT (conT tcn) [ varT $ getTV b | b <- bs]
+  buildT tcn vns = foldl' appT (conT tcn) [ varT vn | vn <- vns ]
 
 -- | Low-level reify interface for record type name.
-reifyRecordType :: Name -> Q ((TypeQ, ExpQ), (Maybe [Name], [TypeQ]))
+reifyRecordType :: Name -> Q (((TypeQ, [Name]), ExpQ), (Maybe [Name], [TypeQ]))
 reifyRecordType recTypeName =
   maybe
   (fail $ "Defined record type constructor not found: " ++ show recTypeName)
@@ -53,7 +54,7 @@
 defineProductConstructor :: Name     -- ^ name of product or record type constructor
                          -> Q [Dec]  -- ^ result template
 defineProductConstructor tyN = do
-  ((tyQ, dtQ), (_, colts))  <- reifyRecordType tyN
+  (((tyQ, _), dtQ), (_, colts))  <- reifyRecordType tyN
   [d| instance ProductConstructor $(foldr (appT . (arrowT `appT`)) tyQ colts) where
         productConstructor = $(dtQ)
     |]
diff --git a/src/Data/Functor/ProductIsomorphic/Unsafe.hs b/src/Data/Functor/ProductIsomorphic/Unsafe.hs
--- a/src/Data/Functor/ProductIsomorphic/Unsafe.hs
+++ b/src/Data/Functor/ProductIsomorphic/Unsafe.hs
@@ -8,9 +8,9 @@
 -- Portability : unknown
 --
 -- This module defines unsafe class interfaces.
-module Data.Functor.ProductIsomorphic.Unsafe
-       ( ProductConstructor (..)
-       ) where
+module Data.Functor.ProductIsomorphic.Unsafe (
+  ProductConstructor (..),
+  ) where
 
 -- | Define product isomorphic inference rule
 --   to specify record constructor