testRegex fails using GHC 7.6.1 and regex-pcre 0.94.4

PCRETest.hs

import Text.Regex.PCRE

regex = "dein(en)? ([^\\s]+)"

expected = [ [ "dein F\252ller", "", "F\252ller"]
           , [ "deinen F\246hn", "en", "F\246hn"]
           ]

-- consider this being read from a file
inputStr = "Nimm dein F\252ller und nimm deinen F\246hn mit."

-- this failes
testRegex :: IO ()
testRegex =
    quickAssert "Regex with umlauts" expected got
    where
      got :: [[String]]
      got = inputStr =~ regex

-- just a helper
quickAssert :: (Show a, Eq a) => String -> a -> a -> IO ()
quickAssert name expect got
    | expect == got = putStrLn $ "> " ++ name ++ ": OK"
    | otherwise =
        do putStrLn $ "> " ++ name ++ ": FAILED"
           putStrLn $ "Expected: " ++ show expect
           putStrLn $ "Got: " ++ show got