Is it possible to be “at work” — and so legally owed the minimum wage — while you are asleep in bed? What if you are behind the wheel of an empty Uber waiting to be assigned a passenger?

These questions were at the heart of two recent UK Supreme Court decisions, to which the judges answered “no” and “yes” respectively. The cases don’t just matter for the parties involved. Taken together, they show the law is incoherent and under-enforced on a matter of growing importance: how we define “work” and ensure people are paid fairly for it, even as the boundaries of the workplace and the working day are beginning to dissolve.

In the Uber case, the judges concluded that drivers were “workers” for the time they were logged into the app and available for rides. The judges reasoned that even when waiting around with no one in the car, the drivers were providing a service to Uber.