Delta Air Lines (DAL) is being sued by passengers who allegedly paid extra for window seats, only to be seated next to a blank wall, a court filing showed Tuesday.

The issue involves certain Boeing (BA) 737 and 757 jets and Airbus A321 aircraft, where some window seats lack actual windows due to the placement of internal components such as air ducts or wiring, according to the filing.

The lawsuit, led by Nicholas Meyer of Brooklyn, argues that the airline operator does not warn travelers about these seats during booking, unlike others such as Alaska Air (ALK) and American Airlines (AAL).

United Airlines (UAL) is also facing a similar class-action lawsuit, Reuters reported, adding that the complaint is led by Marc Brenman of San Francisco and Aviva Copaken of Los Angeles.

Delta and United didn't immediately respond to MT Newswires' requests for comment.