Uber is to roll out a selfie feature on its app so that drivers can verify some riders are wearing face masks.
It will apply to riders who have previously been reported for not wearing a mask.
The selfie scanner, to be used in the US and Canada by the end of September and other regions after that, will look for a mask-like covering over the mouth and nose.
Currently, drivers must take a mask selfie each day before starting work.
If the scanner does not detect the driver is wearing a mask they are blocked from using the app to pick up passengers.
Uber introduced a "No Mask No Ride" policy on 18 May and extended it indefinitely due to the ongoing pandemic, requiring both drivers and riders to wear a face covering at all times during a ride.
Drivers and riders are able to cancel a trip without charge if they report the other party is not wearing a mask. Failure to comply can lead to account deactivation.
Demand for ride-hailing trips fell sharply during the coronavirus lockdown, especially in the US.
In a tweet, Uber boss Dara Khosrowshahi said the move was to help protect drivers and passengers. "We're all in this together," he said.
Uber said it hoped the feature would be a useful reminder of its policy for customers who are just returning to the service.
'No facial recognition'
"We definitely wanted to make sure that we are targeting this feature to riders who are maybe just coming back to the platform and maybe they're not aware of our mask policy," said Sachin Kansal, Uber's senior director of product management.
Uber said the selfie feature does not use facial recognition technology, but simply detects the mask as an object on the face.
The company said it will store the selfie photos for 96 hours to settle potential disputes, but then permanently deletes them, Uber said.
Uber says it has allocated $50m (£37m) worth of masks, gloves, hand sanitiser, sprays and wipes to drivers. The company said it has distributed masks to 1.4 million drivers globally.