The first reference to “soybean milk” in the U.S. showed up in 1897. “Almond milk” appears in medieval cookbooks. But a new bill argues that calling any non-dairy product “milk” confuses consumers.

The DAIRY PRIDE Act (“Defending Against Imitations and Replacements of Yogurt, milk, and cheese to Promote Regular Intake Of Dairy Everyday”), sponsored by Wisconsin Senator Tammy Baldwin, says that any non-dairy product that calls itself “milk” should be considered misbranded, and subject to enforcement by the FDA.

[Photo: Flickr user jm3

The bill comes a month after a coalition of House members sent a letter to the FDA urging it to take action against “fake milk.”

Technically, FDA regulations define milk as the “lacteal secretion” of a cow. But the FDA hasn’t gone after products that use milk as part of a longer name, as in Silk’s “soymilk” or Almond Breeze’s “almondmilk.” In 2015, a federal judge ruled that Trader Joe’s “soy milk” doesn’t mislead consumers into thinking it’s the same as cow milk.

Non-dairy manufacturers argue that “milk” is common usage. “To us, this attempt to legislate the word ‘milk’ as dairy-only comes a little late, and doesn’t make sense considering plant-based milks have been around not only for several years but for centuries,” says Molly Spence, a spokesperson for the Almond Board of California.

The dairy industry, for its part, says that non-dairy products are hijacking their marketing, particularly around nutrition. It’s a case they’ve been trying to make to the FDA since 2000, when the National Milk Producers Federation began petitioning the agency about the use of “soymilk.” The pressure is greater now–as the dairy industry has been shrinking, sales of products such as almond milk have quickly grown.

This battle might sound familiar: For the last few years, eggless-mayo company Hampton Creek has been battling with the egg industry and large mayonnaise manufacturers about what legally constitutes mayo. The two sides came to a somewhat convoluted agreement in December 2015.