Fast-food chain White Castle has unveiled a vegetarian version of its trademark burger.

The nearly century-old company is now offering a vegetarian version of its slider at all of its nearly 400 locations in 12 US states.

The veggie slider will be available for 99 cents and can be topped with three sauces: honey mustard, sweet Thai and ranch. It is a Dr Praeger’s veggie patty and includes carrots, broccoli, zucchini, peas and spinach.

While being filled with more vegetables than the typical White Castle burger, they have a similar caloric load to the traditional burger – coming in with between 150 and 270 calories. The beef version is between 140 and 220 calories.

The veggie burgers were tested during the summer at locations in New York and New Jersey and will be available for a limited time.

White Castle has recently added a variety of cakes on a stick to its menu that includes a Fish Slider, breakfast version of its slider and milk.

Burger King has offered a vegetarian option for several years, and Chipotle this year unveiled a vegan option for its burritos, in addition to already offering a veggie burrito. At west coast burger chain In-n-Out, customers can order an off-menu grilled cheese that bears a close resemblance to its famous sandwich.

McDonald’s, the largest fast food chain in the world, offers a veggie burger at its United Arab Emirates locations, but not in the US.