Over a dozen states filed a brief Friday asking the Supreme Court to make it legal to fire people for being transgender.

The amicus brief, which was signed by 16 states, asks the Court to hear and reverse a case decided in March by the Sixth Circuit Court of Appeals, which ruled in favor of a transgender woman who was fired from her job at a funeral home after she began transitioning from a man to a woman. The Sixth Circuit held that her termination violated Title VII’s protections on the basis of sex.

At the heart of the case is the question of whether the laws protecting people from discrimination on the basis of “sex," include gender identity in the definition. The 16 states supporting the suit have expressed their doubts, calling the appeals court ruling an “egregious error” and “policy experimentation."

"‘Sex’ refers to one’s biological status as male or female, not to a changeable psychological view of one’s gender," the brief argues.

The brief was filed by the Attorneys General in Nebraska, Alabama, Arkansas, Kansas, Louisiana, Oklahoma, South Carolina, South Dakota, Tennessee, Texas, Utah, West Virginia, and Wyoming, and joined by Kentucky Gov. Matt Bevin, Maine Gov. Paul LePage, and Mississippi Gov. Phil Bryant. All are Republican.

The states also argue that because lawmakers have attempted to pass laws protecting gender identity in addition to laws protecting against discrimination on the basis of sex, gender identity and sex cannot be the same thing. Utah and Maine both have state laws prohibiting LGBTQ employment discrimination, though none of the other states included in the brief do.

“The role of the courts is to interpret the law, not to rewrite the law by adding a new, unintended meaning,” the brief concludes.