Users filtering by many roles

Hi :)

According to documentation there is ability to filter users by many roles:
https://developer.zendesk.com/api-reference/ticketing/users/users/#using-curl

I supposed such filtering will return all users with role "admin" along with all users with role "end-user". My intention was to get all users, except "agent", in one request. But API returns no users at all, regardless there are few admins and one end-user:

https://{subdomain}.zendesk.com/api/v2/users.json?role[]=admin
returns 3 users

https://{subdomain}.zendesk.com/api/v2/users.json?role[]=end-user
returns 1 user

https://{subdomain}.zendesk.com/api/v2/users.json?role[]=admin&role[]=end-user
returns nothing

What did i do wrong? :)