The U.S. Department of Justice (DOJ) has filed a brief in support of an Oklahoma law that requires birth certificates to list a person’s biological sex and limits the options to either “male” or “female.”

The DOJ brief, submitted by U.S. Assistant Attorney General Harmeet K. Dhillon, argued that Oklahoma’s law does not discriminate against any citizens and treats everyone the same.

“The policy does not differentiate between male and female applicants and easily passes rational basis muster,” the brief stated.

Oklahoma law states that the sex designation on birth certificates “shall be either male or female and shall not be nonbinary.”

A lawsuit was quickly filed to challenge the law, and a court ruled against the state in Fowler v. Stitt, declaring the law discriminates against transgender-identifying individuals. But the law is now being reviewed again in light of a recent U.S. Supreme Court decision.

The U.S. Department of Justice brief relies heavily on the U.S. Supreme Court’s recent ruling in United States v. Skrmetti, which held that a Tennessee state law that prohibited sex-change surgeries for children did not discriminate against patients based on their self-proclaimed “transgender” identity because the law treated all people the same.

The U.S. Department of Justice made similar arguments in defending Oklahoma’s birth-certificate law, saying there is “no distinction” in the Oklahoma State Department of Health’s “response to an amendment application by a male and a female (or an applicant who identifies as transgender and one who does not).”

The DOJ noted that under Oklahoma law, the state department of health “will only amend birth certificates in limited circumstances, which do not include a desire to change the designated sex—for men or women, transgender or not.”

“Oklahoma’s law uses biological sex on birth certificates for all Oklahomans and declines to provide a special exemption for those who identify as transgender,” the brief stated. “But the State’s refusal to grant such an exemption cannot plausibly be characterized as ‘discrimination.’”

The DOJ brief said Oklahoma’s law is “rationally related to legitimate interests” and “eminently sensible,” saying the birth-certificate law “supports the preservation of vital statistics” and “furthers the State’s interest in protecting women-only spaces,” such as the Oklahoma law barring men from using women’s bathrooms in public schools or participating in girls’ athletics.

“In contrast, the State has no evident interest in maintaining records of individuals’ self-perceived ‘gender identity,’” the DOJ brief stated. “The identity is not immutable … making it of little value for purposes of government identification.”

The brief argued that the State of Oklahoma’s legitimate interests negate the court’s prior decision that claimed the purpose of Oklahoma’s law seemed “inexplicable by anything but animus” toward transgender people.

Under longstanding precedent, the DOJ brief noted that “a court may only infer animus when the challenged law ‘lack[s] any purpose other than a bare desire to harm a politically unpopular group.’”

The Fowler v. Stitt case is back before the U.S. Court of Appeals for the Tenth Circuit, which will reconsider Oklahoma’s law in light of the recent Skrmetti decision.