[Haskell-cafe] Deriving class instances using DrIFT

Hi. I'm trying to derive some instances using DrIFT, but it will only work for me when I'm deriving for types in the current file or in the prelude. For example, this works:

module Test where

{-! for Maybe derive : Haskell2Xml !-}

this works:

module Test where

data Foo = Foo

{-! for Foo derive : Haskell2Xml !-}

but this doesn't:

module Test where

import Data.Word

{-! for Word32 derive : Haskell2Xml !-}

It fails to load the first import, giving an error as follows: {- Generated by DrIFT (Automatic class derivations for Haskell) -} {-# LINE 1 "Test.hs" #-} DrIFT: can't find module Data.Word Any ideas as to why that is? Thanks Daniel