diff --git a/Control/Categorical/Bifunctor.hs b/Control/Categorical/Bifunctor.hs
--- a/Control/Categorical/Bifunctor.hs
+++ b/Control/Categorical/Bifunctor.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE MultiParamTypeClasses, FunctionalDependencies, FlexibleContexts, DefaultSignatures #-}
+{-# LANGUAGE MultiParamTypeClasses, FunctionalDependencies, FlexibleContexts #-}
 -------------------------------------------------------------------------------------------
 -- |
 -- Module   : Control.Categorical.Bifunctor
@@ -25,13 +25,13 @@
 
 class (Category r, Category t) => PFunctor p r t | p r -> t, p t -> r where
     first :: r a b -> t (p a c) (p b c)
-    default first :: Bifunctor p r s t => r a b -> t (p a c) (p b c)
-    first f = bimap f id
+--    default first :: Bifunctor p r s t => r a b -> t (p a c) (p b c)
+--    first f = bimap f id
 
 class (Category s, Category t) => QFunctor q s t | q s -> t, q t -> s where
     second :: s a b -> t (q c a) (q c b)
-    default second :: Bifunctor q r s t => s a b -> t (q c a) (q c b)
-    second = bimap id
+--    default second :: Bifunctor q r s t => s a b -> t (q c a) (q c b)
+--    second = bimap id
 
 -- | Minimal definition: @bimap@ 
 
@@ -40,13 +40,13 @@
     bimap :: r a b -> s c d -> t (p a c) (p b d)
     -- bimap f g = second g . first f
 
-instance PFunctor (,) (->) (->)
-instance QFunctor (,) (->) (->)
+instance PFunctor (,) (->) (->) where first f = bimap f id
+instance QFunctor (,) (->) (->) where second = bimap id
 instance Bifunctor (,) (->) (->) (->) where
     bimap f g (a,b)= (f a, g b)
 
-instance PFunctor Either (->) (->)
-instance QFunctor Either (->) (->)
+instance PFunctor Either (->) (->) where first f = bimap f id
+instance QFunctor Either (->) (->) where second = bimap id
 instance Bifunctor Either (->) (->) (->) where
     bimap f _ (Left a) = Left (f a)
     bimap _ g (Right a) = Right (g a)
diff --git a/Control/Categorical/Functor.hs b/Control/Categorical/Functor.hs
--- a/Control/Categorical/Functor.hs
+++ b/Control/Categorical/Functor.hs
@@ -18,13 +18,21 @@
     , LoweredFunctor(..)
     ) where
 
+#ifndef MIN_VERSION_base
+#define MIN_VERSION_base(x,y,z) 1
+#endif
+
 import Control.Category
 import Prelude hiding (id, (.), Functor(..))
 import qualified Prelude
 #ifdef __GLASGOW_HASKELL__
 import Data.Data (Data(..), mkDataType, DataType, mkConstr, Constr, constrIndex, Fixity(..))
+#if MIN_VERSION_base(4,4,0)
 import Data.Typeable (Typeable1(..), TyCon, mkTyCon3, mkTyConApp, gcast1)
+#else
+import Data.Typeable (Typeable1(..), TyCon, mkTyCon, mkTyConApp, gcast1)
 #endif
+#endif
 
 -- TODO Data, Typeable
 newtype LiftedFunctor f a = LiftedFunctor (f a) deriving (Show, Read)
@@ -32,7 +40,11 @@
 #ifdef __GLASGOW_HASKELL__
 
 liftedTyCon :: TyCon
+#if MIN_VERSION_base(4,4,0)
 liftedTyCon = mkTyCon3 "categories" "Control.Categorical.Functor" "LiftedFunctor"
+#else
+liftedTyCon = mkTyCon "Control.Categorical.Functor.LiftedFunctor"
+#endif
 {-# NOINLINE liftedTyCon #-}
 
 liftedConstr :: Constr
@@ -63,7 +75,11 @@
 #ifdef __GLASGOW_HASKELL__
 
 loweredTyCon :: TyCon
+#if MIN_VERSION_base(4,4,0)
 loweredTyCon = mkTyCon3 "categories" "Control.Categorical.Functor" "LoweredFunctor"
+#else
+loweredTyCon = mkTyCon "Control.Categorical.Functor.LoweredFunctor"
+#endif
 {-# NOINLINE loweredTyCon #-}
 
 loweredConstr :: Constr
diff --git a/Control/Category/Dual.hs b/Control/Category/Dual.hs
--- a/Control/Category/Dual.hs
+++ b/Control/Category/Dual.hs
@@ -14,13 +14,21 @@
   ( Dual(..)
   ) where
 
+#ifndef MIN_VERSION_base
+#define MIN_VERSION_base(x,y,z) 1
+#endif
+
 import Prelude (undefined,const,error)
 import Control.Category
 
 #ifdef __GLASGOW_HASKELL__
 import Data.Data (Data(..), mkDataType, DataType, mkConstr, Constr, constrIndex, Fixity(..))
+#if MIN_VERSION_base(4,4,0)
 import Data.Typeable (Typeable2(..), TyCon, mkTyCon3, mkTyConApp, gcast1)
+#else
+import Data.Typeable (Typeable2(..), TyCon, mkTyCon, mkTyConApp, gcast1)
 #endif
+#endif
 
 data Dual k a b = Dual { runDual :: k b a }
 
@@ -35,7 +43,11 @@
           asDualArgsType = const
 
 dataTyCon :: TyCon
+#if MIN_VERSION_base(4,4,0)
 dataTyCon = mkTyCon3 "categories" "Control.Category.Dual" "Dual"
+#else
+dataTyCon = mkTyCon "Control.Category.Dual.Dual"
+#endif
 {-# NOINLINE dataTyCon #-}
 
 dualConstr :: Constr
diff --git a/categories.cabal b/categories.cabal
--- a/categories.cabal
+++ b/categories.cabal
@@ -1,6 +1,6 @@
 name:          categories
 category:      Control
-version:       1.0.2
+version:       1.0.3
 license:       BSD3
 cabal-version: >= 1.10
 license-file:  LICENSE