The online dating service Tinder must change one of its key monetization strategies. A Los Angeles appellate court reversed a lower court's decision on Monday and told Tinder to stop charging older users more money per month for its "Tinder Plus" service.

The proposed class-action lawsuit, filed by Tinder user Allan Candelore in February 2016, alleged that Tinder engaged in illegal age discrimination by charging its 30-and-older users $19.99 per month for Tinder Plus while offering younger users either $9.99 or $14.99 monthly subscription rates for the same services. Tinder Plus includes app perks such as additional "super-likes" which are more likely to attract a dater's response.

In an initial trial, Tinder's defense argued that the pricing was based on market testing that showed a market-driven reason to offer lower prices to "budget constrained" users.

"Nothing in the [original] complaint suggests there is a strong public policy that justifies the alleged discriminatory pricing," Judge Brian Currey wrote in the appeal court's 3-0 ruling. "Accordingly, we swipe left"—a joke based on the app's popular "swipe to reject" gesture—"and reverse."

That reversal hinges largely on California's Unruh Civil Rights Act, which was passed in 1959 and protects "equal access to public accommodations and prohibits discrimination by business establishments." The ruling noted that some business-led discrimination is allowed by California state law, but it agreed with Candelore's argument that Tinder's age-targeted pricing is not.

Wednesday's ruling cited the 1982 California State Court case of Marina Point Ltd. v. Wolfson , in which a landlord had refused to rent housing to anyone with "minor children." Much as that landlord had unsuccessfully argued protection due to the "unruly" nature of children, Tinder's arguments also failed. The company claimed its market research and understanding about age-based pricing somehow got around the requirements of the Unruh Act. (Judge Currey also acknowledged other trials' rulings about age-based pricing differences for children and seniors being upheld, then stated that the Marina Point's specific issues were more relevant to the ruling at hand.)

The ruling did not include financial terms beyond noting that "Candelore is entitled to his costs." In a report from NBC News, Candelore's attorney Al Rava pointed out that the ruling's impact could include "thousands of potential class members."

Tinder did not immediately respond to Ars' questions as to whether the company would appeal the ruling to the California Supreme Court or if it would also change this age-based pricing model for users outside of California.