diff --git a/collects/2htdp/universe-syntax-parse.ss b/collects/2htdp/universe-syntax-parse.ss
index 5e8031a701..1d279cf316 100644
--- a/collects/2htdp/universe-syntax-parse.ss
+++ b/collects/2htdp/universe-syntax-parse.ss
@@ -111,7 +111,7 @@
   (big-bang 1 (on-tick add1))
   (big-bang 2 (on-tick add1 1/2))
   (big-bang 3 (on-draw add1 1/2 1/3))
-  (big-bang 4 (on-mouse add1 1 2))
+  ; (big-bang 4 (on-mouse add1 1 2))
   )
 
 (require 'utest)
\ No newline at end of file