Get Xchat-Gnome completing with colon

Since the late nineties, I’ve had my IRC clients configured to complete nicks with a colon. For example:

<jml> dash: there's an otherwise normal guy at work who uses tcl as his scripting language of choice

But during some Ubuntu upgrade at some point in the last couple of years, Xchat-Gnome changed my settings without telling me. Now it completes nicks like this:

<jml> itamar, a cunning, enviable balance between argument and unsupported assertion

Which is so clearly inferior to a colon-based nick-completion that I do not have to list the reasons. There are many.

In any case, today I figured out how to change it:

/set completion_suffix :

That’s it. Xchat will take care of saving the configuration for you. I’m so happy.

Update: Actually, no, Xchat does not take care of saving the configuration for you.

You must open ~/.xchat2/xchat.conf, find the line that says completion_suffix = , and change it to say completion_suffix = : and then, crucially, save your changes to that file. You’ll probably have to restart Xchat as well.