Enable Alt + Ctrl + Backspace in Ubuntu 9.04

By default Alt + Ctrl + Backspace (kill X-Server) is disabled in Ubuntu 9.04. There is a note in Ubuntu 9.04 Release Notes:

Ctrl-Alt-Backspace is now disabled, to reduce issues experienced by users who accidentally trigger the key combo. Users who do want this function can enable it in their xorg.conf, or via the command dontzap --disable.

Well, I'm one of the users who are using Alt + Ctrl + Backspace. So, how did I enable this wonderful combination? I haven't tried dontzap --disable, but, instead of that, I added some magical lines to my /etc/X11/xorg.conf:

Section "ServerFlags" Option "DontZap" "false" EndSection

After this you need to restart X-Server (not with Alt + Ctrl + Backspace - now it doesn't work) and then you can use this combination :)