Ford is recalling 410,289 F-Series trucks in the U.S. equipped with engine block heaters due to a fire risk. An additional 463,793 trucks in Canada are also being recalled.

According to the notice submitted to NHTSA, water and contaminants can corrode and damage the heater cable’s splice connector and cause a short. Ford says it is only a danger when the truck is plugged into an electrical outlet.

2015-2019 F-150 and 2017-2019 F-Series Super Duty models with block heaters are affected, and the parts will either be repaired or replaced.

Ford is aware of three fires, but no accidents or injuries related to the issue.