diff --git a/collects/tests/unstable/temp-c/ex-matthias-ctc.rkt b/collects/tests/unstable/temp-c/ex-matthias-ctc.rkt
index aaadd43d53..081e477f18 100644
--- a/collects/tests/unstable/temp-c/ex-matthias-ctc.rkt
+++ b/collects/tests/unstable/temp-c/ex-matthias-ctc.rkt
@@ -19,7 +19,7 @@
   (define a (send memory malloc))
   (test
    (send memory free a) 
-   (send memory free "foo") =error> #rx"expected \\<number"
+   (send memory free "foo") =error> #rx"expected: number\\?"
    (send memory free a)))
 
 (require 'b)