diff --git a/collects/tests/compiler/zo-test-worker.rkt b/collects/tests/compiler/zo-test-worker.rkt
index 022d661058..e73f0630bb 100644
--- a/collects/tests/compiler/zo-test-worker.rkt
+++ b/collects/tests/compiler/zo-test-worker.rkt
@@ -260,7 +260,7 @@
 (define (run-test file)
   (run-with-limit 
    file
-   (* 1024 1024 1024)
+   (* 1024 1024 512)
    (lambda ()
      (run! file)))
   (write (reverse RESULTS)))