diff --git a/PArrows.cabal b/PArrows.cabal
--- a/PArrows.cabal
+++ b/PArrows.cabal
@@ -1,8 +1,9 @@
 Name:            PArrows
-Version:         0.1
+Version:         0.1.1
 License:         BSD3
 License-File:    LICENSE
 Author:          Einar Karttunen <ekarttun@cs.helsinki.fi>
+Maintainer:      none
 Stability:       Alpha
 Category:        Parsing
 Synopsis:        Arrow parser combinators similar to Parsec
@@ -11,12 +12,13 @@
                  .
                  Currently PArrows is only tested with GHC, although making it work with Hugs should be easy.
 Homepage:        http://www.cs.helsinki.fi/u/ekarttun/PArrows/
-Build-Depends:   base>3, containers, mtl
-Build-Type:      Simple
-Tested-With:     GHC==6.8.2
 
+Build-Depends:   base>3, containers, mtl, ghc-prim
+Build-Type:      Simple
+Tested-With:     GHC==6.10
+cabal-version:   >= 1.2.3
 Extensions:      FlexibleContexts, FunctionalDependencies, MagicHash, GADTs
-Ghc-Options:     -O2 -Wall
+Ghc-Options:     -Wall
 
 Hs-Source-Dirs:  src
 Exposed-Modules: Text.ParserCombinators.PArrow,
diff --git a/src/Text/ParserCombinators/PArrow/Char.hs b/src/Text/ParserCombinators/PArrow/Char.hs
--- a/src/Text/ParserCombinators/PArrow/Char.hs
+++ b/src/Text/ParserCombinators/PArrow/Char.hs
@@ -47,5 +47,5 @@
 
 -- | Match a constant string.
 string :: String -> MD i String
-string []  = pure (\_ -> "")
-string str = pure (\_ -> ' ') >>> foldr1 (>>>) (map char str) >>> pure (\_ -> str)
+string []  = arr (\_ -> "")
+string str = arr (\_ -> ' ') >>> foldr1 (>>>) (map char str) >>> arr (\_ -> str)
diff --git a/src/Text/ParserCombinators/PArrow/Combinator.hs b/src/Text/ParserCombinators/PArrow/Combinator.hs
--- a/src/Text/ParserCombinators/PArrow/Combinator.hs
+++ b/src/Text/ParserCombinators/PArrow/Combinator.hs
@@ -13,7 +13,7 @@
 
 -- | Match one or more occurences of the given parser.
 many1 :: MD i o -> MD i [o]
-many1 x = (x &&& MStar x) >>> pure (\(b,bs) -> (b:bs))
+many1 x = (x &&& MStar x) >>> arr (\(b,bs) -> (b:bs))
 
 -- | Match if the given parser does not match.
 notFollowedBy :: MD i o -> MD i o
diff --git a/src/Text/ParserCombinators/PArrow/MD.hs b/src/Text/ParserCombinators/PArrow/MD.hs
--- a/src/Text/ParserCombinators/PArrow/MD.hs
+++ b/src/Text/ParserCombinators/PArrow/MD.hs
@@ -3,8 +3,10 @@
 module Text.ParserCombinators.PArrow.MD (MD(..)) where
 
 import Control.Arrow
+import Control.Category
 import Data.List (intersperse)
 import GHC.Prim (unsafeCoerce#)
+import Prelude hiding (id,(.))
 import Text.ParserCombinators.PArrow.CharSet
 
 data MD i o where
@@ -35,9 +37,12 @@
 force :: MD a b -> MD c d
 force = unsafeCoerce#
 
+instance Category MD where
+    b . a = a `MSeq` b
+    id    = arr id
+
 instance Arrow MD where
     arr f    = MPure "" f
-    a >>> b  = a `MSeq` b
     a *** b  = a `MParWire` b
     a &&& b  = a `MJoin` b
     first a  = a `MParWire` ("id" `MPure` id)