intelliJ not opening correct version of browser

System: Ubuntu 17.04

For testing purpose, I have installed old version of mozilla along with latest one. I want the intelliJ to run test cases in old version. I followed this guide https://www.jetbrains.com/help/idea/configuring-browsers.html.

When I locally host the webApp, it automatically opens up in old version of mozilla as expected but on running the tests, intelliJ uses the latest version with profile of old version resulting in failure of test cases.

What do I do?

Thanks