Walmart could soon start eating DoorDash and Uber Eats’ lunch as it begins to experiment in the restaurant delivery space.On Thursday, Walmart announced it would begin delivering Subway items as part of Express Delivery this month, either on its own or alongside other products such as groceries. Customers will pay a flat Walmart Express Delivery fee as they do for other items. There are roughly 1,400 Subway locations inside Walmart stores, making it the company’s largest in-store restaurant tenant.

Walmart’s ambitions in restaurant deliveries are far larger than Subway, however. The company has built the groundwork for a restaurant ordering experience within the Walmart app and website, allowing customers to customize food items and sharing the checkout screen with other items.

The company is looking to eventually expand to other restaurants within Walmart stores, Tracy Poulliot, evp of e-commerce and marketing for Walmart U.S., told reporters Thursday. Greg Cathey, svp of digital fulfillment transformation for Walmart, said this could eventually extend to restaurants outside of Walmart stores.

“Almost all quick-service restaurant brands are located within five miles of Walmart; we think it’s a natural revolution over time to think through thoughtfully how we expand this service,” Cathey said. “Our first priority right now is we need to really focus on our in-store tenants and providing this service for them.”