hide user roles tab

[iHuman]

How can I hide the 'User Roles' tab from the owner account?

With this visible, the owner could actually setup a new user role that allows a higher level of permissions than I've granted them on the site.

I know I can turn off manage users - but I want them to be able to add and delete users based on roles I have pre-defined - without the ability to add their own custom roles.

thanks,
elaine