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diff --git a/testsuite/tests/simplCore/should_run/T3437.hs b/testsuite/tests/simplCore/should_run/T3437.hs
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+++ b/testsuite/tests/simplCore/should_run/T3437.hs
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+{-# LANGUAGE BangPatterns #-}
+{-# OPTIONS_GHC -O2 #-}
+
+-- Trac #3437
+-- When we do SpecConstr on 'go', we want the specialised
+-- function to *still* be strict in k.  Otherwise we get
+-- a bad space leak!
+
+-- The test is run with +RTS -M10m to limit the amount of heap
+-- It should run in constant space, but if the function isn't 
+-- strict enough it'll run out of heap
+
+module Main where
+
+go :: [Int] -> [Int] -> [Int]
+go (0:xs) !k = k
+go (n:xs) !k = go (n-1 : xs) (k ++ k)
+
+main = print (go [100000000] [])