About 3.7 million toddler car seats have been recalled because some harness buckles could become stuck in the latched position, manufacturer Graco said.

The voluntary recall includes the buckles used on toddler convertible seats and harnessed booster seats made between 2009 and July 2013, the company’s website said.

Graco said food and dried liquids could lead to the harness problem. An improved replacement harness is available at no cost. The company tells consumers to call its customer service team for details at (800) 345-4109 or email them at consumerservices@gracobaby.com.