In what is apparently not an April Fools’ joke, Impossible Foods and Burger King are launching an Impossible Whopper

The meat substitute manufacturer Impossible Foods and fast food giant Burger King are launching an Impossible Whopper.

According to a report in The New York Times, Burger King is launching the Impossible Whopper in stores in the St. Louis area with plans for a broader rollout later — and not as part of some elaborate April Fools’ Day prank.

Burger King isn’t the first fast food chain to bring an Impossible burger to market. That’d be White Castle, which is selling Impossible sliders at stores in the Northeast.

But Burger King would certainly be the biggest slinger of ground beef to go with a meatless patty maker.

Impossible’s largest competition in the meat-substitute market, the publicly traded purveyor of purely beef-free patties, Beyond Meat, has a similar deal with Carl’s Jr. for its own version of a beef-less burger.

The Silicon Valley-based Impossible Foods has been on a roll. They introduced a new version of their burger to much fanfare at the Consumer Electronics Show earlier this year, and have been locking in deals with higher-end fast casual restaurants and now large international fast food chains.

In the eight years since the company raised its first $7 million investment from Khosla Ventures, Impossible Foods has managed to amass more than $389 million in financing — including a convertible note last year from the Singaporean global investment powerhouse Temasek (which is backed by the Singaporean government) and the Chinese investment fund Sailing Capital (a state-owned investment fund backed by the Communist Party-owned Chinese financial services firm, Shanghai International Group).

It remains to be seen if this is a harbinger of things to come for Burger King and whether the fast food giant will embrace other alternative meat companies like the providers of fake chicken or cellular-based meat substitutes like Memphis Meats.