McDonald’s and Pizza Hut, the two biggest American fast food chains for hamburgers and pizza, are venturing into plant-based meat analogue products.

McDonald’s plans to introduce “McPlant” items, including burgers, chicken and breakfast foods, into seleced test markets next year. McDonald’s had conducted a test of a plant-based patty from Beyond Meat earlier this year at some Canadian outlets, but the company did not specify who would be supplying the meat-analogue products for the U.S. test.

“It’s not a matter of if McDonald’s gets into plant-based, it’s when,” CEO Chris Kempczinski told investors.

Meanwhile, Beyond Meat’s plant-based sausage will be used on pizzas available at all Pizza Hut locations in the U.S. They will use a sausage crumble developed jointly by Beyond Meat and Pizza Hut.

Pizza Hut had tested a pizza last year using plant-based sausage from Incogmeato, the meat analogue unit of Kellogg.