diff --git a/ghc/tests/simplCore/should_compile/Simpl006Help.hs b/ghc/tests/simplCore/should_compile/Simpl006Help.hs
new file mode 100644
index 0000000000000000000000000000000000000000..4356a28f23c31cfa611d339d297c6990d3bfe36f
--- /dev/null
+++ b/ghc/tests/simplCore/should_compile/Simpl006Help.hs
@@ -0,0 +1,5 @@
+{-# OPTIONS -O #-}
+
+module Simpl006Help( forever ) where
+
+forever c  = sequence_ (repeat c)
diff --git a/ghc/tests/simplCore/should_compile/simpl006.hs b/ghc/tests/simplCore/should_compile/simpl006.hs
new file mode 100644
index 0000000000000000000000000000000000000000..81e43a5b79a87255e737d70725f97d87a99c7f3d
--- /dev/null
+++ b/ghc/tests/simplCore/should_compile/simpl006.hs
@@ -0,0 +1,19 @@
+-- !!! This one sent 4.06 into an infinite loop
+
+-- But it worked ok if Simpl006Help.forever is 
+-- defined in this module.  I have no idea why!
+
+{-# OPTIONS -O #-}
+
+module ShouldCompile where
+
+import Concurrent 
+import Simpl006Help
+
+after :: Int -> IO a -> IO a
+after d c = c
+
+every :: Int -> IO a -> IO ()
+every d c = forever (after d c)
+
+