I recently installed LXDE in Ubuntu 11.10, so that I can choose it at the login screen, but I've since noticed that there's no compose key (since I enabled it in Gnome Shell and Unity) so I was wondering how to enable a compose key?

Thanks for any help :)

4 Answers 4


setxkbmap -option "compose:caps" for CapsLock

setxkbmap -option "compose:ralt" for right alt =)

  • 1
    Hi, I did that for the right alt, but then I did it for the right ctrl instead, is there anyway to get rid of the one for the right alt, as now I can't use the Euro sign, as Alt gr doesn't work anymore, thanks :) Nov 5, 2011 at 16:15
  • 2
    This messes up other keys on my machine.
    – l0b0
    Apr 12, 2012 at 15:00
  • This doesn't work for my with Lubuntu in a Virtualbox. Instead altgr opens up the context menu. Any further suggestions? How do I tell if the setting was correctly applied? How can I tell LXDE to unbind the menu behavior from AltGr? Jan 27, 2014 at 12:49

To set the compose key

sudo leafpad /etc/default/keyboard

edit XKBOPTIONS to like this


To get a list of available keys:

grep compose /usr/share/X11/xkb/rules/xorg.lst

Reboot for the change to be applied or

setxkbmap -option "compose:Shift+AltGr"

To check if the option was set correctly

setxkbmap -print -verbose 10


press Shift then AltGr and release then click on "o c" to obtain ©.

Additional reading

  • Excellent answer! I might add that after editing /etc/default/keyboard a simple login/logout maneuver (which usually is enough when people say 'reboot') did not work for me (on Lubuntu 16.04). After a proper reboot it worked however!
    – zrajm
    Sep 11, 2017 at 22:56

You can check if the keyscan code on your keyboard same as default setting. Did you check if you can do the compose by selecting predefined keyboard with Compose key?


For iBus, you can use

setxkbmap -option "lv3:ralt_switch_multikey"

This is defined in /usr/share/X11/xkb/rules/ as "Right Alt [for 3rd level], Shift+Right Alt key is Compose"

This is also included when you select the gb layout:

setxkbmap -layout gb

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