Kakao Mobility, the firm behind South Korea’s leading taxi-hailing service, Kakao T, announced Sunday that the company would allow drivers with good ratings from passengers to enjoy a better chance of getting booked.

New contract terms will apply to taxi drivers who newly subscribe to Pro Membership, a paid membership program designed to help them pick up more passengers.

Under the new terms, Kakao Mobility may deny membership to drivers with low ratings or boot existing subscribers if their ratings slip below a certain level.

Kakao Mobility passengers can already rate drivers, giving them one to five stars depending on the quality of the riding experience. But until now the rating system was used only to create an average rating for each driver that passengers could refer to when hailing taxis.

Kakao Mobility expects the change to lead to improved services for passengers.

Taxi drivers, however, are crying foul over the introduction of a paid membership program, as well as the rating system, saying the firm is abusing its market dominance.

Kakao Mobility’s share of the domestic ride-hailing market is estimated to surpass 80 percent.