diff --git a/collects/2htdp/tests/robby-optimization-gone.ss b/collects/2htdp/tests/robby-optimization-gone.ss
index fb70329b00..528df04b92 100644
--- a/collects/2htdp/tests/robby-optimization-gone.ss
+++ b/collects/2htdp/tests/robby-optimization-gone.ss
@@ -17,8 +17,4 @@
                        (set! s (string-append "-" s))
                        (rectangle 1 1 'solid 'green)))))
 
-(let ([s (make-semaphore)])
-  (queue-callback (λ () (semaphore-post s)))
-  (yield s))
-
 (unless (string=? s "---") (error 'world-update-test "failed! ~s" s))