New York (CNN Business) Burger King has a plan to bring in new customers and encourage existing ones to buy more often: Vegetarian Whoppers.

The burger chain announced on Monday that it is testing out Impossible Whoppers, made with plant-based patties from Impossible Foods, in 59 locations in and around St. Louis. If all goes well, Burger King will roll out the Impossible Whopper nationally.

With the Impossible Whopper, Burger King hopes to "give somebody who wants to eat a burger every day, but doesn't necessarily want to eat beef everyday, permission to come into the restaurants more frequently," Chris Finazzo, president of Burger King North America, told CNN Business. It's also a way to encourage vegan and vegetarian eaters to check out Burger King.

The chain has been trying to figure out a way to add a plant-based burger option to its menu for about a year, Finazzo said.

"There's a lot of interest in plant-based burgers," he noted.

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