diff --git a/pkgs/racket-test-core/tests/racket/subprocess.rktl b/pkgs/racket-test-core/tests/racket/subprocess.rktl
index 0fbd7ef60a..09d93148cd 100644
--- a/pkgs/racket-test-core/tests/racket/subprocess.rktl
+++ b/pkgs/racket-test-core/tests/racket/subprocess.rktl
@@ -467,7 +467,7 @@
                  (let loop ()
                    (when (running? sub-pid)
                      (sleep 0.05)
-                     (loop (sub1 n)))))
+                     (loop))))
                (test post-shutdown? running? sub-pid)
                (when post-shutdown?
                  (parameterize ([current-input-port (open-input-string "")])