The National Highway Traffic Safety Administration has issued a recall of more than 50,000 school buses.

The NHTSA says the bus seat backs may not give enough impact absorption around the back of the seat frame, adding that the buses do not comply with the federal safety requirements.

The recall affects 53,528 buses 2014 through 2020, including:

  • Saf-T-Liner EFX
  • Minotour
  • Saf-T-Liner C2
  • Safe-T-Liner HDX

Daimler Trucks North America, owner of the Thomas Built Buses company, will notify owners of the affected buses and dealers will add padding between the frame and the seat cover at no cost.

The recall begins Dec. 2.