Repeated evaluation of pure expression in IO action

Question

I have a procedure that (a) does some IO, (b) constructs a lookup table, and (c) returns an IO action that uses the lookup table. But when compiled with -O, GHC (version 6.12.1) inlines the construction the lookup table, so that it is reevaluated for every call of the IO action.

Example:

module Main where
import Data.Array
import Data.IORef
import Control.Monad

makeAction getX getY sumRef = do
    x <- getX
    let a = listArray (0, 1000) [x ..]
    return $ do
        y <- getY
        modifyIORef sumRef (\sum -> sum + a ! y)

main = do
    sumRef <- newIORef 0
    action <- makeAction getX getY sumRef
    replicateM_ 100000 action
    n <- readIORef sumRef
    putStrLn (show n)
    where
    getX = return (1 :: Int)
    getY = return 0

Is this issue well-known enough to have a standard GHC-foolproof workaround - or how would you adjust the program so that a isn't repeatedly being allocated?