[Haskell-cafe] Bug in HLint or haskell-src-exts?

Hello Haskellers, I've got the following piece of code type Memory addr value = Map.Map addr value type Stack item = [item] data MachineState addr value item = MachineState { memory :: Memory addr value , stack :: Stack item } deriving (Show) newtype Machine addr value item m a = Machine { unMachine :: StateT (MachineState addr value item) m a } deriving (Monad, MonadState (MachineState addr value item), MonadTrans, MonadIO) and HLint complains: Machine.hs:20:31: Parse failure, Parse error This is exactly the position of the opening bracket after MonadState. Why can GHC parse this and HLint cannot? Regards, Martin.