Oklahoma’s Republican governor signed an executive order Tuesday aimed at limiting the rights of transgender people in the state, and trans women in particular.

Known as “The Women’s Bill of Rights” by supporters, the order requires state agencies to define the words “female” and “male” based on a person’s sex assigned at birth. Specifically, it defines a female as a “person whose biological reproductive system is designed to produce ova” and a male as a “person whose biological reproductive system is designed to fertilize the ova of a female,” the Associated Press reports. It also defines the words “man,” “boy,”

Oklahoma’s new law will force trans youth to detransition, even though every major medical association opposes it.

“Today we’re taking a stand against this out-of-control gender ideology that is eroding the very foundation of our society,” Gov. Kevin Stitt (R) said at a signing ceremony on Tuesday. “We are going to be safeguarding the very essence of what it means to be a woman.”

“Oklahomans are fed up with attempts to confuse the word ‘woman’ and turn it into some kind of ambiguous definition that harms real women,” he continued.

Stitt was joined by members of Independent Women’s Voice (IWV), a conservative, anti-trans nonprofit organization, and former University of Kentucky swimmer Riley Gaines. Gaines has become a prominent anti-trans voice advocating against trans women competing in women’s sports since tying for fifth place with University of Pennsylvania swimmer Lia Thomas, who is transgender, in the 2022 NCAA freestyle championship.

In Tweets on Tuesday, Gaines and IWV characterized the order as protecting cisgender women’s rights and safety.

“Stitt is the first governor to take decisive action and safeguard women’s privacy, safety, and equal opportunities,” Gaines tweeted.

“Thank you @GovStitt for signing an executive order to implement the #WomensBillofRights,” IWV tweeted. “Your leadership is a recognition that sex-defintions matter and women deserve to have access to private spaces when safety and fairness require.”

Nicole McAfee, executive director of Freedom Oklahoma, called Stitt’s executive order a “thinly veiled attack” on the rights of transgender women. “This executive order is neither about rights, nor is it about protecting women,” McAfee said.

The executive order is the latest attack on transgender rights in Oklahoma. In May, Stitt signed a law banning gender-affirming healthcare for anyone under 18 and making it a felony for doctors to provide such care to trans youth. Last year, he signed a law requiring transgender students to use school bathrooms that correspond with the sex they were assigned at birth, another banning trans girls from participating in school sports, and a third banning nonbinary gender markers on birth certificates in Oklahoma.