Nearly 40,000 Mustangs may be affected by a Ford recall triggered by defective brake pedal bracket assemblies.

The bracket may fracture or, in the worst-case scenario, could snap leaving drivers without an effective brake pedal. The consequences of a broken brake pedal hardly need to be outlined.

Submitted on September 23, the recall includes 38,005 Mustangs. The recall only affects cars with an automatic transmission, since the manual transmission models use a different pedal bracket.

According to the National Highway Traffic Safety Administration, the problem stems from Ford’s use of a new material for the assembly. The switch from nylon to polypropylene (the same plastic used in TicTac lids, for instance) “resulted in reduced robustness to spike stop loading for the particular design,” according to NHTSA.

The new pedal assembly is limited to model year 2020 Mustangs and, naturally, the company has stopped using it. Ford is so far unaware of any incidents relating to the defect, but the consequences of losing a brake pedal could be severe.

Ford will contact owners and will replace the bracket assembly free of charge.