diff --git a/equal-files.cabal b/equal-files.cabal
--- a/equal-files.cabal
+++ b/equal-files.cabal
@@ -1,5 +1,5 @@
 Name:           equal-files
-Version:        0.0.2
+Version:        0.0.2.1
 License:        GPL
 License-File:   LICENSE
 Author:         Henning Thielemann <haskell@henning-thielemann.de>
diff --git a/src/EqualFiles.hs b/src/EqualFiles.hs
--- a/src/EqualFiles.hs
+++ b/src/EqualFiles.hs
@@ -1,8 +1,8 @@
 module Main where
 
 import System.Environment (getArgs, )
-import qualified Data.ByteString as B
-import Data.List (groupBy, sort, intersperse, )
+import qualified Data.ByteString.Lazy as B
+import Data.List (groupBy, sort, )
 
 
 groupEqualElems :: (Ord key, Ord elem) => [(elem, key)] -> [[key]]
@@ -22,6 +22,6 @@
 -- output results in a quoted way that might be accessible to further shell scripts
 main :: IO ()
 main =
-   mapM_ (putStrLn . concat . intersperse " " . map show) =<<
+   mapM_ (putStrLn . unwords . map show) =<<
    clusterEqualFiles =<<
    getArgs