diff --git a/collects/tests/racket/contract-mzlib-test.rktl b/collects/tests/racket/contract-mzlib-test.rktl
index fbcf500..b85e305 100644
--- a/collects/tests/racket/contract-mzlib-test.rktl
+++ b/collects/tests/racket/contract-mzlib-test.rktl
@@ -4178,7 +4178,7 @@ so that propagation occurs.
   (test-name 'printable/c printable/c)
   (test-name '(or/c 'a 'b 'c) (symbols 'a 'b 'c))
   (test-name '(or/c 1 2 3) (one-of/c 1 2 3))
-  (test-name '(one-of/c '() 'x 1 #f #\a (void) (letrec ([x x]) x)) 
+  (test-name '(or/c '() 'x 1 #f #\a void? undefined?)
              (one-of/c '() 'x 1 #f #\a (void) (letrec ([x x]) x)))
   
   (test-name '(subclass?/c c%)