Karma Firefox Doesn't Work With HTTPS

When I run Karma tests they fail as Firefox (as ran by Karma) won't except my certificate (i'm using https).

I'm using Karma to run integration tests on a NodeJs Firefox add-on. I'm testing it on my localhost machine using XAMPP's Apache. I've created ssl local keys, configured Apache to use the keys and when i'm trying it manually everything looks good. The problem only appears when Karma runs a FF profile. I tried installing the certificate globally on all profiles but that wasn't an option.

Thanks in advance!