General Motors Co is recalling nearly 19,000 of its all-new 2014 Chevrolet Silverado and GMC Sierra pickup trucks to repair a problem with the manual reclining seatback, according to a notice from U.S. auto safety regulators on Friday.

On some of the trucks, the front seats may have a defect in the reclining mechanism. As a result, the seatbacks fail to comply with federal auto safety standards on head restraints.

“If the vehicle is struck from behind, the head restraint may not properly protect occupants, increasing the risk of injury,” according to the notice posted on the National Highway Traffic Safety Administration website.

The recalled models were built between August 1 and September 10. GM’s truck roll-out began in June and represents the most important vehicle launch for the No. 1 U.S. automaker since its 2009 bankruptcy restructuring.

GM told truck owners about the defect in the first half of October. NHTSA could not review the owner notification letter due to the 16-day government shutdown, which tempered auto sales growth in October.