diff --git a/monoid-transformer.cabal b/monoid-transformer.cabal
--- a/monoid-transformer.cabal
+++ b/monoid-transformer.cabal
@@ -1,5 +1,5 @@
 Name:             monoid-transformer
-Version:          0.0.1
+Version:          0.0.2
 License:          BSD3
 License-File:     LICENSE
 Author:           Henning Thielemann <haskell@henning-thielemann.de>
@@ -10,6 +10,7 @@
 -- Portability:      Haskell 98
 Description:
   Monoid transformers: State, Reader
+  .
   There is no Writer transformer.
   It's vice versa: The Writer monad transforms a monoid to a monad.
 Tested-With:       GHC==6.8.2
@@ -23,11 +24,11 @@
 Source-Repository this
   type:     darcs
   location: http://code.haskell.org/~thielema/monoid/
-  tag:      0.0.1
+  tag:      0.0.2
 
 
 Library
-  Build-Depends: base
+  Build-Depends: base >= 1 && <5
 
   GHC-Options:      -Wall
   Hs-Source-Dirs:   src
diff --git a/src/Data/Monoid/Reader.hs b/src/Data/Monoid/Reader.hs
--- a/src/Data/Monoid/Reader.hs
+++ b/src/Data/Monoid/Reader.hs
@@ -6,6 +6,9 @@
 
 newtype T r a = Cons {run :: r -> a}
 
+pure :: a -> T r a
+pure = Cons . const
+
 instance Monoid a => Monoid (T r a) where
    mempty = MonoidTrans.lift mempty
    mappend (Cons x) (Cons y) =
@@ -13,3 +16,6 @@
 
 instance MonoidTrans.C (T r) where
    lift = Cons . const
+
+instance Functor (T r) where
+   fmap f (Cons g) = Cons (f . g)
diff --git a/src/Data/Monoid/State.hs b/src/Data/Monoid/State.hs
--- a/src/Data/Monoid/State.hs
+++ b/src/Data/Monoid/State.hs
@@ -3,8 +3,21 @@
 import qualified Data.Monoid.Transformer as MonoidTrans
 import Data.Monoid (Monoid, mempty, mappend, )
 
+{- |
+This resembles the pure State monad.
+However, State in transformers is a StateT
+and mtl is not Haskell 98.
+
+I hope I have the more natural parameter order for 'evaluate'
+in contrast to @mtl@ and @transformers@.
+However, it is different from the parameter order of 'run'.
+-}
 newtype T s a = Cons {run :: s -> (a,s)}
 
+pure :: a -> T s a
+pure a = Cons $ \s -> (a,s)
+
+
 evaluate :: s -> T s a -> a
 evaluate s m = fst $ run m s
 
@@ -27,5 +40,13 @@
              (yr,s2) = y s1
          in  (mappend xr yr, s2)
 
-instance MonoidTrans.C (T r) where
+instance MonoidTrans.C (T s) where
    lift x = Cons $ (,) x
+
+instance Functor (T s) where
+   fmap f (Cons g) = Cons (mapFst f . g)
+
+-- from utility-ht
+{-# INLINE mapFst #-}
+mapFst :: (a -> c) -> (a,b) -> (c,b)
+mapFst f ~(a,b) = (f a, b)