diff --git a/beautiful-racket-demo/stackerizer-demo/stackerizer.rkt b/beautiful-racket-demo/stackerizer-demo/stackerizer.rkt
index a6b06f5..e06f134 100644
--- a/beautiful-racket-demo/stackerizer-demo/stackerizer.rkt
+++ b/beautiful-racket-demo/stackerizer-demo/stackerizer.rkt
@@ -3,7 +3,8 @@
 
 (define-macro (stackerizer-mb EXPR ...)
   #'(#%module-begin
-     (for-each displayln (reverse (flatten EXPR ...)))))
+     (for-each displayln
+               (reverse (flatten (list EXPR ...))))))
 (provide (rename-out [stackerizer-mb #%module-begin]))
 
 (define-macro (define-ops OP ...)