diff --git a/collects/tests/racket/mzlib-tests.rktl b/collects/tests/racket/mzlib-tests.rktl
index b0a35143e2..78f46d3118 100644
--- a/collects/tests/racket/mzlib-tests.rktl
+++ b/collects/tests/racket/mzlib-tests.rktl
@@ -32,5 +32,6 @@
 (load-in-sandbox "macrolib.rktl")
 (load-in-sandbox "resource.rktl")
 (load-in-sandbox "syntaxlibs.rktl")
+(load-in-sandbox "subprocess.rktl")
 
 (report-errs)
diff --git a/collects/tests/racket/subprocess.rktl b/collects/tests/racket/subprocess.rktl
index 94e182b4be..49685c3069 100644
--- a/collects/tests/racket/subprocess.rktl
+++ b/collects/tests/racket/subprocess.rktl
@@ -342,7 +342,7 @@
 
 (let ([no-nuls (lambda (thunk)
                  (err/rt-test (thunk) (lambda (exn)
-                                        (regexp-match? #rx"without nuls" (exn-message exn)))))])
+                                        (regexp-match? #rx"bytes-no-nuls[?]" (exn-message exn)))))])
   (no-nuls (lambda () (subprocess #f #f #f cat "\0")))
   (no-nuls (lambda () (subprocess #f #f #f cat #"\0")))
   (no-nuls (lambda () (process "\0")))