diff --git a/src/gui/client/main-window.lisp b/src/gui/client/main-window.lisp
index 0a9de98..abcd0d2 100644
--- a/src/gui/client/main-window.lisp
+++ b/src/gui/client/main-window.lisp
@@ -1377,7 +1377,7 @@
 
 (defun init-main-window ()
   (setf gui:*debug-tk* nil)
-  (gui:with-nodgui (:title +program-name+)
+  (gui:with-nodgui (:title +program-name+ :debugger-class 'gui:graphical-condition-handler)
     (icons:load-icons)
     (setf gui-goodies:*toplevel* gui:*tk*)
     (setf gui-goodies:*gui-server* gui:*wish*)