diff --git a/pkgs/racket-test/tests/racket/prompt-sfs.rkt b/pkgs/racket-test/tests/racket/prompt-sfs.rkt
index 41549471b6..94632df8f5 100644
--- a/pkgs/racket-test/tests/racket/prompt-sfs.rkt
+++ b/pkgs/racket-test/tests/racket/prompt-sfs.rkt
@@ -20,7 +20,7 @@ process.
     (let ([p (open-output-bytes)])
       (parameterize ([current-error-port p])
         (system* f "-l" "tests/racket/prompt-sfs" "sub"))
-      (unless (regexp-match? #rx"<will-executor>: +1 +" (get-output-bytes p))
+      (unless (regexp-match? #rx"<will-executor>:? +1 +" (get-output-bytes p))
         (error "wrong output")
         (exit 1))))
   (exit 0))
diff --git a/pkgs/racket-test/tests/racket/stress/fuzz.rkt b/pkgs/racket-test/tests/racket/stress/fuzz.rkt
index 61468f0809..841d548fa1 100644
--- a/pkgs/racket-test/tests/racket/stress/fuzz.rkt
+++ b/pkgs/racket-test/tests/racket/stress/fuzz.rkt
@@ -97,7 +97,11 @@
 
 (module+ test
   (require racket/vector syntax/location)
-  (parameterize ([current-command-line-arguments (vector-append #("-c") (current-command-line-arguments))])
-    (dynamic-require (quote-module-path ".." main) #f))
+  (cond
+    [(eq? 'racket (system-type 'vm))
+     (parameterize ([current-command-line-arguments (vector-append #("-c") (current-command-line-arguments))])
+       (dynamic-require (quote-module-path ".." main) #f))]
+    [else
+     (printf "This test only works when (system-type 'vm) is 'racket\n")])
   (module config info
     (define random? #t)))
diff --git a/pkgs/racket-test/tests/racket/stress/module-stack.rkt b/pkgs/racket-test/tests/racket/stress/module-stack.rkt
index ef9bee0150..01a90e081e 100644
--- a/pkgs/racket-test/tests/racket/stress/module-stack.rkt
+++ b/pkgs/racket-test/tests/racket/stress/module-stack.rkt
@@ -24,7 +24,10 @@
   (void
    (let loop ([i 0])
      (vector-set-performance-stats! results)
-     (if (zero? (vector-ref results 5))
+     (if (and (zero? (vector-ref results 5))
+              ;; No "stack overflow" on Chez Scheme, so pick a depth
+              (or (eq? 'racket (system-type 'vm))
+                  (i . < . 50000)))
          (let ([v (loop (add1 i))])
            (if (zero? v)
                (begin
diff --git a/pkgs/racket-test/tests/units/test-unit.rkt b/pkgs/racket-test/tests/units/test-unit.rkt
index 9f996c4a7a..1e1a56452c 100644
--- a/pkgs/racket-test/tests/units/test-unit.rkt
+++ b/pkgs/racket-test/tests/units/test-unit.rkt
@@ -1094,9 +1094,9 @@
   (define u1 (unit (import) (export x-sub y-sub) (define x 1) (define xx 2) (define y 3) (define yy 4)))
   (define-values/invoke-unit u1 (import) (export x-sig))
   (test 1 x)
-  (test-runtime-error exn? "xx: undefined;\n cannot reference an identifier before its definition" xx)
-  (test-runtime-error exn? "y: undefined;\n cannot reference an identifier before its definition" y)
-  (test-runtime-error exn? "yy: undefined;\n cannot reference an identifier before its definition" yy))
+  (test-runtime-error exn? "xx: undefined;\n cannot reference" xx)
+  (test-runtime-error exn? "y: undefined;\n cannot reference" y)
+  (test-runtime-error exn? "yy: undefined;\n cannot reference" yy))
 
 (let ()
   (define u1 (unit (import) (export x-sig) (define x 1)))
@@ -2062,9 +2062,9 @@
 
   (test 'zero (use-unit))
   (test 'zero (use-unit2))
-  (test-runtime-error exn:fail:contract:variable? "u-a: undefined;\n cannot reference an identifier before its definition"
+  (test-runtime-error exn:fail:contract:variable? "u-a: undefined;\n cannot reference"
                       (use-unit-badly1 u-a))
-  (test-runtime-error exn:fail:contract:variable? "u-a: undefined;\n cannot reference an identifier before its definition"
+  (test-runtime-error exn:fail:contract:variable? "u-a: undefined;\n cannot reference"
                       (use-unit-badly2 sig^))
 
   (test 12