How to prevent my custom .conf files from "Ubuntu Mate Updates/Upgrades"

Hi!

How to prevent my custom .conf (modified) files from “Ubuntu Mate Updates/Upgrades”.

I chattr +i some custom “.conf” of some programs/files, that is working, but when I try to make an Update via Update-Manager, sometimes a package/program don’t let me update/upgrade because the chattr attribute is set of the file.

What can I do to prevent Ubuntu Mate Update-Manager to overwrite my "custom .conf (modified) files?

I'll do it now with:

sudo chattr +i file.conf