diff --git a/lisp-koans/koans/macros.lisp b/lisp-koans/koans/macros.lisp
index d088dee..daeece6 100644
--- a/lisp-koans/koans/macros.lisp
+++ b/lisp-koans/koans/macros.lisp
@@ -111,6 +111,9 @@
 ;; but yes, for gensym limit ,stop is evaluated first
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; advice on checking intermediate things inside of let / flet / etc
+;; (*print-gensym*) ; so that gensyms could be copied into repl
+(declaim (optimize 'debug))
 
 (define-test for
     (macrolet ((for ((var start stop) &body body)
@@ -129,6 +132,7 @@
                (return-3 () (push 3 side-effects) 3))
           (for (i (return-0) (return-3))
             (push i result)))
+        (break)
         (assert-equal '(0 1 2 3) (nreverse result))
         (assert-equal '(0 3) (nreverse side-effects)))))