General Motors is recalling 686,287 vehicles equipped with the optional power liftgate, including Chevrolet Traverse and GMC Acadia SUV models, because the liftgate is at risk for falling, the National Highway Traffic Safety Administration said.

The recall affects 2008-2012 model-year Buick Enclave, 2009-2012 Chevrolet Traverse, 2007-2012 GMC Acadia, and 2007-2010 Saturn Outlook mid-size SUVs equipped with the power liftgate option. The gas struts that hold the power liftgate up when it’s open might prematurely wear, which could lead to the liftgate falling suddenly. This may potentially injure someone, NHTSA said.

Dealers will update the software for the power liftgate actuator motor control unit so that the motor will prevent the rapid closing of the liftgate. This will prevent the wear-and-tear on the struts. There will be no charge for the repair.

Vehicle owners can contact Buick customer service at (800) 521-7300, Chevrolet customer service at (800) 222-1020, GMC customer service at (800) 462-8782, and Saturn customer service at (800) 553-6000. GM’s number for this recall is 15240.