Do you work shifts or in shifts?

Do you work shifts or in shifts?
 

What´s the correct do you work in shifts or do you work shifts?

In a generalization, people work in shifts:

The Health Service has the policy that nurses always work in shifts. :good:
The firemen worked around the clock in shifts to rescue people from the collapsed building. :good:

With a specific person describing his/her job, they work shifts:

I hate my job because I have to work shifts. :good:

Exactly as in Spanish.