diff --git a/examples/Test.hs b/examples/Test.hs
--- a/examples/Test.hs
+++ b/examples/Test.hs
@@ -12,6 +12,7 @@
 import Generics.Regular
 import Generics.Regular.Functions.Arbitrary
 import Generics.Regular.Functions.Binary
+import Generics.Regular.Functions.Seq
 
 import Test.QuickCheck (quickCheck, sized, elements, generate, Gen)
 import qualified Test.QuickCheck as Q (Arbitrary(..))
@@ -88,3 +89,6 @@
           propL :: Logic -> Bool
           propL x = runGet gget (runPut (gput x)) == x
       in quickCheck propC >> quickCheck propL
+
+-- Testing deep seq
+ex4 = gdseq (Not (T :->: (error "deep seq works"))) ()
diff --git a/regular-extras.cabal b/regular-extras.cabal
--- a/regular-extras.cabal
+++ b/regular-extras.cabal
@@ -1,5 +1,5 @@
 name:                   regular-extras
-version:                0.1.2
+version:                0.2.0
 synopsis:               Additional functions for regular: arbitrary,
                         coarbitrary, and binary get/put.
 description:
@@ -11,7 +11,7 @@
   \[1] <http://hackage.haskell.org/package/regular>
 
 category:               Generics
-copyright:              (c) 2009 Universiteit Utrecht
+copyright:              (c) 2010 Universiteit Utrecht
 license:                BSD3
 license-file:           LICENSE
 author:                 Jose Pedro Magalhaes,
@@ -20,7 +20,7 @@
 stability:              experimental
 build-type:             Custom
 cabal-version:          >= 1.2.1
-tested-with:            GHC == 6.10.4
+tested-with:            GHC == 6.10.4, GHC == 6.12.1
 extra-source-files:     examples/Test.hs
                         ChangeLog
 
@@ -28,10 +28,12 @@
 library
   hs-source-dirs:       src
   exposed-modules:      Generics.Regular.Functions.Arbitrary,
-                        Generics.Regular.Functions.Binary
+                        Generics.Regular.Functions.Binary,
+                        Generics.Regular.Functions.Seq
 
   other-modules:        Generics.Regular.Functions.Fixpoints
   
-  build-depends:        base >= 4.0 && < 5, regular >= 0.2 && < 0.3,
-                        QuickCheck == 1.2.0.0, binary >= 0.2
+  build-depends:        base >= 4.0 && < 5, regular >= 0.3 && < 0.4,
+                        QuickCheck == 1.2.0.0, binary >= 0.2,
+                        deepseq < 2
   ghc-options:          -Wall
diff --git a/src/Generics/Regular/Functions/Seq.hs b/src/Generics/Regular/Functions/Seq.hs
new file mode 100644
--- /dev/null
+++ b/src/Generics/Regular/Functions/Seq.hs
@@ -0,0 +1,57 @@
+{-# LANGUAGE TypeOperators            #-}
+{-# LANGUAGE FlexibleContexts         #-}
+{-# LANGUAGE FlexibleInstances        #-}
+
+-----------------------------------------------------------------------------
+-- |
+-- Module      :  Generics.Regular.Functions.Seq
+-- Copyright   :  (c) 2009 Universiteit Utrecht
+-- License     :  BSD3
+--
+-- Maintainer  :  generics@haskell.org
+-- Stability   :  experimental
+-- Portability :  non-portable
+--
+-- Summary: Deep generic seq. Used to fully evaluate a term.
+-----------------------------------------------------------------------------
+
+module Generics.Regular.Functions.Seq (
+  
+    Seq(..), gdseq
+  
+  ) where
+
+import Control.DeepSeq
+import Generics.Regular.Base
+
+-- | The class for generic deep seq.
+class Seq f where
+  gseq :: (a -> b -> b) -> f a -> b -> b
+
+instance Seq I where
+  gseq f (I x) = f x
+
+-- | For constants we rely on the |DeepSeq| class.
+instance (NFData a) => Seq (K a) where
+  gseq _ (K x) = deepseq x
+  
+instance Seq U where
+  gseq _ U = id
+
+instance (Seq f, Seq g) => Seq (f :+: g) where
+  gseq f (L x) = gseq f x
+  gseq f (R y) = gseq f y
+
+instance (Seq f, Seq g) => Seq (f :*: g) where
+  gseq f (x :*: y) = gseq f x . gseq f y
+
+instance Seq f => Seq (C c f) where
+  gseq f (C x) = gseq f x
+
+instance Seq f => Seq (S s f) where
+  gseq f (S x) = gseq f x
+
+
+-- | Deep, generic version of seq.
+gdseq :: (Regular a, Seq (PF a)) => a -> b -> b
+gdseq p = gseq gdseq (from p)