NHTSA issued the first recall of the Tesla Semi, due to a potential problem with the parking brake that could result in a rollaway. While we’re still not sure how many Semis have been delivered to customers so far, the recall affects 35 examples of the electric truck, and their owners will be notified by a letter this May.

These 35 Tesla Semis may have an issue with the electronic parking brake valve module (PVM), which was supplied by Bendix Commercial Vehicle Systems LLC. According to NHTSA, the component “could fail to move into parking position when the parking brake is activated”. This could lead to the truck rolling away, when the driver engages the parking brake and releases the brake pedal, potentially leading to an accident.

Read: Report Claims Tesla Semi Breakdowns Linked To Glitch That That May Turn Off Screen

 Tesla Semi Gets Its First Recall Over Parking Brake Glitch That Could Lead To Rollaways

The issue became known by the supplier in February, and following Tesla’s investigation, the decision was taken for a voluntary recall. Thankfully the recall comes before any known incidents. Owners of the affected Semis can visit a Tesla service station to have their PVMs replaced free of charge. Tesla’s technicians will use a revised part featuring “improved internals that prevents air leakage” resulting in seamless engagement and disengagement of the parking brake.

Notification letters will be sent on May 23, but interested parties can contact Tesla customer service or NHTSA earlier than that.

The recall comes after at least eight known breakdown incidents of the Tesla Semi, which were left stranded and then towed to a “secret” location in California. Those cases probably had nothing to do with the parking brake, but some of them were reportedly caused by malfunctioning screens. It remains to be seen if Tesla will issue another recall and if major software issues are hiding behind the stranded Semis.

 Tesla Semi Gets Its First Recall Over Parking Brake Glitch That Could Lead To Rollaways