Walmart has signed a deal with ThredUp, an e-commerce company that buys and sells secondhand clothes, shoes and accessories. As per this deal, customers can now browse thousands of pre-owned items for women and children on the big-box retailer’s website. They can get free shipping from Walmart, so long as they spend $35 or more. And if purchases don’t work out, they can return the items at a nearby store.

Walmart is also expanding its online fashion assortment at a time when it could grab market share in apparel and accessories. Its deal with ThredUp is a way to expand its online fashion offerings and get in on the sustainability trend. ThredUp bills itself as the largest online thrift store. Customers can send in clothes, shoes, handbags and more, so long as they’re in good condition. If they pass a quality inspection and sell, he or she gets a portion of the profits. The San Francisco-based resale company has over 45,000 brands, ranging from designer names like Marc Jacobs to fast fashion like Forever 21.

Walmart dominates the grocery business, but despite its efforts, it is still lags in fashion. It has acquired plus-sized women’s apparel company Eloquii and menswear company Bonobos, developed exclusive apparel lines with Ellen DeGeneres and Sofía Vergara and revived Scoop, a trendy brand that used to have stores in New York City.

ThredUp has struck deals with a growing number of retailers, including Gap, Macy’s and J.Crew-owned Madewell. Many of its partnerships with retailers have had a brick-and-mortar rather than e-commerce focus.