The fast-food chain on Thursday unveiled the Chicken Big Mac, a major (though limited-time) twist on the burger that has been around since 1968.

Sales of the Chicken Big Mac will begin Oct. 10 at participating restaurants, though the company gave people in Los Angeles a sneak peek last weekend, opening up a faux-knock-off pop-up diner called McDonnell’s and offering the sandwich along with deep-fried apple pie, another old favorite of fast-food junkies.

The re-thought Big Mac will feature two tempura-battered chicken patties, in place of the two all-beef patties. (Special sauce, lettuce, cheese, pickles, onions and a sesame-seed bun will still be part of the sandwich’s makeup.)

“With the introduction of the Chicken Big Mac, we’re excited to pay homage to one of our most iconic menu items, the Big Mac, and introduce it to a whole new generation of fans,” said Tariq Hassan, chief marketing and customer experience officer at McDonald’s USA in a statement.

Chicken sandwiches, though, have become an increasingly important menu item for all fast-food chains. Chick-fil-A’s growing popularity and ability to lure customers away put the issue on the radar of major chains, but it was the launch of Popeye’s chicken sandwich on Aug. 12, 2019, that truly lit the fire.

It wasn’t long before every fast-food restaurant announced plans to roll out a new or upgraded chicken sandwich of its own. McDonald’s quickly began testing two versions of a chicken sandwich in several states. The Crispy Chicken Sandwich was topped with butter and crinkle-cut dill pickles, while the Deluxe Chicken Sandwich is topped with tomatoes, lettuce, and mayo. Both are served on a buttered potato roll.

Wendy’s debuted a Jalapeño Popper Sandwich and Shake Shack added a chicken sandwich with a spicy-sweet gochujang glaze. Even Taco Bell got in on the action eventually.

McDonald’s did not say how long the Chicken Big Mac would be available.