Apple on Thursday was hit with a proposed class action accusing the tech giant of paying more than 12,000 female employees in California less than men with comparable jobs, lawyers for the plaintiffs said.

The lawsuit filed in state court in San Francisco by two women claims Apple systematically underpays female workers in its engineering, marketing, and AppleCare divisions, according to a release from the lawyers.

Apple bases workers’ starting pay on their salaries at previous jobs or on their “pay expectations,” which results in lower pay rates for women, according to the release.

The lawsuit also claims that Apple’s performance evaluation system, which it uses to set raises and bonuses, is biased against women, the lawyers said.

Apple did not immediately respond to a Reuters request for comment.