For the next month, the Impossible Whopper will be available at Burger Kings across the country

Starting in one week, the Impossible Foods plant-based Impossible Burger will be available at Burger King restaurants across the country.

The world’s second largest fast food chain is rolling out the Impossible Whopper nationwide at all of its 7,200 U.S. locations for the next month as it tests the potential demand for the meaty-tasting meatless patty.

Burger King first launched the Impossible Whopper at 59 restaurants in the St. Louis area on April Fool’s day. But the joke seems to be on the restaurant chain for not trying to make the nationwide rollout happen sooner.

Foot traffic to restaurants that sold the Impossible Whopper soared a whopping 18.5%, according to the market analysis firm, inMarket Insights. Over the same period, foot traffic to the company’s restaurants elsewhere in the U.S. declined 1.75%, according to the study, which analyzed location data of 50 million Comscore-verified users.

It’s been a busy week for Impossible Foods, which announced only yesterday that it had inked a partnership with a manufacturer to boost supplies of its heavily in-demand patties. The company also cleared the final regulatory hurdle it faced to bring its Impossible Burgers to grocery stores around the country. So just as Burger King wraps up its trial run, customers across the country will be able to find the patties on store shelves.

Burger King wasn’t the first chain to see the value in adding Impossible Burgers to the menu. Roughly a year ago, White Castle became the first major fast food chain to offer an Impossible Slider on its menu. The burgers can also be found at more upscale fast-casual restaurant chains like Bareburger, Applebee’s, Red Robin, and Five Napkin Burger joints.

While the other chains may have been first, the Burger King rollout is by far the largest.

“From the launch of our test in St. Louis, we knew that our guests really enjoyed the taste of the flame-grilled Impossible Whopper,” said Chris Finazzo, President, North America, Burger King Corporation, in a statement. “We’re now making the Impossible Whopper available for our guests across the country at an unbeatable price for a limited time only so visit one of our restaurants before they sell out.”

One day after the in-store launch, Burger King and DoorDash will offer an “Impossible Taste Test” where customers can order an Impossible Whopper and the original sandwich for $7. For orders of $10 or more, DoorDash will waive the delivery fee.

Suggested retail price for the Impossible Whopper is $5.59, which also puts the burger at a lower price point than many of the other fast food chains slinging Impossible products.

While the Impossible Whopper may be made entirely of plants, it’s not much healthier than eating a regular burger. The patties, made of water, soy protein, coconut oil, sunflower oil and leghemoglobin (that’s the company’s secret ingredient) aren’t designed to be healthier option than a burger — they’re just designed to be a more environmentally conscious replacement for beef.

Impossible Foods’ recent wins come as its chief rival, Beyond Meat, is raking in piles of cash as a publicly traded company and building up a sizable war chest to conduct research and development for new products.

Impossible Foods has raised nearly $700 million to date as a private company. Its backers include  Khosla Ventures,  Bill Gates, Google Ventures, Horizons Ventures, UBS, Viking Global Investors, Temasek, Sailing Capital and Open Philanthropy Project.