Following the lead of rivals American Airlines and Delta, United will soon charge an extra fee for economy-class seating closest to the front of the cabin, USA Today reports.

The extra fees will be charged for seating in the first rows behind United’s Economy Plus section of the cabin. Unlike the larger Economy Plus seats, however, these seats will not differ from other economy seats.

Pricing has not yet been announced. United said certain frequent flyers and corporate customers would continue to be able to reserve preferred seating at no extra charge.

The fees will be charged beginning later in 2018. On other airlines, the fee structure for preferred economy seats varies: American, for example, charges between $4 and $139 for the privilege of reserving seats near the front of the economy section.

Delta is currently charging $60 for preferred economy window and aisle seats located behind its Delta Comfort Plus rows.

Other economy class seats on United will continue to be available for assignment free of charge.