diff --git a/scan.cabal b/scan.cabal
--- a/scan.cabal
+++ b/scan.cabal
@@ -1,7 +1,7 @@
 cabal-version:      >= 1.4
 build-type:         Simple
 name:               scan
-version:            0.1.0.8
+version:            0.1.0.9
 license:            BSD3
 license-file:       doc/LICENSE
 category:           Development
@@ -16,8 +16,16 @@
 homepage:           http://projects.haskell.org/style-scanner
 stability:          experimental
 
+flag parsec1
+    Description: Use parsec1
+    Default: False
+
 executable scan
-    build-depends:      base < 5, parsec
+    if flag(parsec1)
+        build-depends: parsec1
+    else
+        build-depends: parsec
+    build-depends:      base < 5
     hs-source-dirs:     src
     main-is:            scan.hs
     other-modules:      Language.Haskell.Scanner
diff --git a/src/scan.hs b/src/scan.hs
--- a/src/scan.hs
+++ b/src/scan.hs
@@ -22,6 +22,7 @@
 import System.Environment
 import System.Console.GetOpt
 import System.Exit
+import System.IO
 
 import Text.ParserCombinators.Parsec
 import Text.ParserCombinators.Parsec.Pos
@@ -35,7 +36,7 @@
 
 -- | the hard-coded version string.
 version :: String
-version = "scan-0.1.0.8 http://projects.haskell.org/style-scanner/"
+version = "scan-0.1.0.9 http://projects.haskell.org/style-scanner/"
 
 data Flag =
     Help
@@ -170,12 +171,18 @@
         putStrLn "missing file argument"
         exitFailure
 
+readByteFile :: FilePath -> IO String
+readByteFile f = openBinaryFile f ReadMode >>= hGetContents
+
+writeByteFile :: FilePath -> String -> IO ()
+writeByteFile f = withBinaryFile f WriteMode . flip hPutStr
+
 {- | process a file. A first true arguments only shows diagnostics.
 A first false argument writes back a modified file, but only if there are
 modifications. -}
 process :: Maybe (FilePath, Maybe FilePath) -> Opts -> FilePath -> IO ()
 process out opts f = do
-  str <- readFile f
+  str <- readByteFile f
   let ls = lines str
       wcsr = map (checkLine (lineLength opts) f) (zip [1 ..] ls)
       wcs = map fst wcsr
@@ -211,9 +218,9 @@
           case mbak of
             Nothing -> return ()
             Just bak -> do
-              writeFile bak str
+              writeByteFile bak str
               putStrLn $ "created backup file: " ++ bak
-          writeFile ofile rstr
+          writeByteFile ofile rstr
           putStrLn $ "wrote file: " ++ ofile
     Left err -> do
       prDiags cs