How to add 'awesome' selection in LightDM?

I installed awesome using apt-get, and after installation finished, I logged out to lightdm.

But there is no selection for awesome, only Unity and subtle (since I recently installed subtle).

What should I do, in order to make awesome selection is available?

There were no errors while installing awesome.

Apparently, it looks like a bug, although some of the users found that switching NoDisplay=true to NoDisplay=false in /usr/share/xsessions/awesome.desktop was enough (see the comments under the bug description). If this solution works out for you, can you also contribute to the bug report in the link given? :)