General Motors has ordered a stop sale for 2019-2020 Chevrolet Silverado and GMC Sierra models as it initiates a large recall for the pickup trucks over a fire risk.

The automaker said on Friday the latest-generation trucks may be prone to a fire breaking out in the event of a crash where the seatbelt pretensioners activate. The gas that allows the pretensioners to work could release and interact with other materials, and ultimately, start a fire. Total, GM said over 640,000 Chevy Silverado and GMC Sierra models are included.

Models included are the Silverado 1500, 2500 and 3500, as well as the Sierra 1500, 2500 and 3500 with carpeted floors.

In documents filed with the National Highway Traffic Safety Administration, the automaker added details surrounding the problem. Pretensioner gases could vent through an opening in the pretensioner bracket and potentially ignite the truck’s carpeted floor on fire.

So far, the company is not aware of accidents, injuries or fatalities involving the safety defect. However, it noted in a statement that it is aware of two fires related to this issue.

As for the stop sale, GM said dealers may not allow these trucks to leave the dealership until repairs are completed. Unfortunately, the automaker does not have a timeline for when it will notify owners and dealers of when the fix will take place. It does have a fix ready, though.

Owners will need to bring their Chevy or GMC pickup to the dealer where a technician will close off the opening in the pretensioner at no charge.