diff --git a/gtk/examples/tic-tac-toe.scm b/gtk/examples/tic-tac-toe.scm
index 93e323b..8c67896 100644
--- a/gtk/examples/tic-tac-toe.scm
+++ b/gtk/examples/tic-tac-toe.scm
@@ -34,6 +34,9 @@ exec guile-gnome-2 -s $0 "$@"
   buttons
   winning-combinations

+  ;; adding foo-bar-baz signal breaks tic-tac-toe with
+  ;; ERROR: Throw to key `gruntime-error' with args `("gsignal-query" "Unknown signal ~A on class ~A" (tic-tac-toe #<<gobject-class> <tic-tac-toe>>) ())'.
+  :gsignal '(foo-bar-baz #f)
   :gsignal '(tic-tac-toe #f))

 (define (ttt-clear ttt)
@@ -119,6 +122,7 @@ exec guile-gnome-2 -s $0 "$@"
   (show-all w)
   (g-timeout-add 100 (lambda () #t))
   (connect ttt 'tic-tac-toe (lambda (ttt) (display "Yay!\n")))
+  (connect ttt 'foo-bar-baz (lambda (ttt) (display "Nay!\n")))
   (connect w 'delete-event (lambda (ttt e) (gtk-main-quit) #f)))

 (gtk-main)