Lenovo is recalling over 80,000 ThinkPad X1 Carbon laptops because they potentially pose a fire hazard.

The laptops actually contain an unfastened screw inside that can damage the lithium-ion battery, and trigger overheating or a fire, Lenovo said on Monday.

The problem applies to fifth-generation ThinkPad X1 laptops sold between Dec. 2016 and Nov. 2017, according to the US Product Safety Commission. About 78,000 of these models were sold to the US, while another 5,500 were sold to Canada.

Lenovo has released a support document that can help customers identify whether they own an affected laptop. The company is offering the inspections and repairs free-of-charge.

So far, Lenovo hasn't received any reports of the faulty X1 Carbons hurting anyone. However, the vendor is still suggesting that affected laptop owners immediately stop using the product. Lithium-ion batteries are known to easily catch fire or even explode whenever punctured. The damage can cause the battery cells inside to short circuit and spark a buildup of heat that can quickly become dangerous.

Lenovo said it learned about the issue several weeks ago. Three customers had reported their laptops overheating, resulting in damage to the products. The PC maker conducted an investigation, and found the culprit: a small unfastened screw that had been left in laptops during their manufacture. Lenovo has since fixed the problem on the supply side.

The company has a website that can help customers locate a warranty provider to perform the repair service. U.S. and Canada residents can also contact Lenovo Services at 1 800-426-7378 for help.