More than one tester?

[StefanPajovic]

This is probably not a bug, but I've wanted to check can there be more than one tester in Kiwi TCMS?
So far, we've had a manager and me as the default tester but now we are adding another colleague to the team as a tester. However, he cannot create test cases, i.e. put his e-mail in the "Default tester" field. Why is this so and is there a way to have two testers?