Three lactose-intolerant women are steamed over a surcharge for nondairy milk substitutions in Starbucks beverages.

California residents Maria Bollinger, Dawn Miller and Shunda Smith filed a lawsuit earlier this month in the U.S. District Court for the Eastern District of California, alleging the coffee giant discriminated against customers lactose allergies by charging them an extra fee for nondairy alternatives to its coffee-based drinks and other beverages. 

“Starbucks charges customers with lactose intolerance and milk allergies an excessively high Surcharge to substitute Non-Dairy Alternatives in its drinks,” according to the complaint, which seeks restitution as well as monetary damages.

The “excessively high” fee alleged in the suit involves a surcharge ranging from 50 cents to 80 cents on Starbucks beverages that contain nondairy, lactose-free options, such as soy, almond, coconut, oat and other plant-based milks. 

Lactose intolerance, which affects 30 million to 50 million Americans, qualifies as a disability under the Americans with Disabilities Act (ADA). The plaintiffs claim that by charging extra for plant-based milks in their beverages, Starbucks violated their rights under the ADA and California Unruh Civil Rights Act, a law that bars businesses from discriminating against residents of the state on the basis of age, race, sex, disability and other criteria. 

A Starbucks spokesperson said the company can’t comment on pending litigation, but noted that domestic customers do have nondairy options at no extra charge. 

“In U.S. Starbucks stores, at no additional cost, customers can add up to four ounces of nondairy milk to hot or iced brewed coffee or tea, cold brew and Americano beverages,” the spokesperson said. 

Members of the Starbucks’ Rewards loyalty program also can redeem points to get nondairy milk when it is not part of the standard recipe.

“Additionally, customers can choose to customize any beverage with a non-dairy milk on the menu for an additional charge. This is similar to other beverage customizations, such as an additional espresso shot or syrup, the Starbucks spokesperson added, noting that pricing varies by market. 

Starbucks isn’t the only restaurant chain to come under fire for tacking on charges for plant-based milk. Dunkin’ in January was hit with a similar suit, while a number of other coffee sellers around the country are also being called out for nondairy milk charges.