Recover last argument of the last command in bash' vi mode

I've been using _ (in normal mode) to do that. I've found it documented here http://www.catonmat.net/download/bash-vi-editing-mode-cheat-sheet.txt .

It's easy to remember too:

• $_ expands to the last argument
• <Esc> + _ types it out

For me it works when I add the following to my .inputrc:

$if mode=vi
"\e.":yank-last-arg
$endif

Then, when changing it in bash on the fly, the .inputrc must be read again:

set -o vi
bind -f .inputrc

Now, I can get the last argument with alt+..