Allbirds, on Thursday, launched a resale platform called Allbirds ReRun that allows customers to trade in their Allbirds shoes for a $20 store credit.

Initially, the program will be available in three stores located in Los Angeles, Chicago and New York City. The company has plans to expand the program in the future.

In a press release, the company said it would sell the imperfect and gently worn shoes on its website. Allbirds currently resells shoes on the site. The company also said it would accept used shoes in unsaleable condition and recycle or donate them, but the items must qualify for the $20 credit.

To create a more sustainable fashion economy, it’s crucial that we take a holistic approach,” said Hana Kajimura, head of sustainability, Allbirds. “By launching our trade-in program, ReRun, we will enable our customers to play an integral role in extending the life of our shoes. We always seek partners who share our commitment to sustainability, and we’re thrilled to work with Trove on our first re-commerce initiative.”