[Haskell] ASCII higher than 127

How was that with Haskell and Unicode??? While up to ghc-6.4.2 the following function worked it now doesn't compile: isSpezGermanChar :: Char -> Bool isSpezGermanChar 'ä' = True isSpezGermanChar 'ö' = True isSpezGermanChar 'ü' = True isSpezGermanChar 'Ä' = True isSpezGermanChar 'Ö' = True isSpezGermanChar 'Ü' = True isSpezGermanChar 'ß' = True isSpezGermanChar _ = False (For those of you who will only read garbage it are/were some letters from the german alphabet.) I hoped we move forward to easier internationalization. Any ideas what to do now? (I would like to keep the code readable and not use '\220' and so on. Thanks, Andreas