A Missouri federal court issued a historic ruling Wednesday stating that a gay man has the right to sue his employer for discrimination.

A three-judge panel from the Missouri Court of Appeals claimed that the state’s prohibition on gender-based bias in the workplace applies to “all employees, regardless of gender identity or sexual orientation.” Judge Anthony Rex Gabbert claimed that LGBTQ people often face discrimination based on noncompliance with expectations of their sex.

“If an employer mistreats a male employee because the employer deems the employee insufficiently masculine, it is immaterial whether the male employee is gay or straight,” Gabbert wrote.

The case was first brought forward by Harold Lampley in 2014, a former employee in the State of Missouri’s Office of Child Support Enforcement Division. Lampley claims that his bosses treated him differently because his gender presentation “contradicted… stereotypes of maleness.” He further alleges that superiors scored him more negatively on performance evaluations after complaining about the homophobia he experienced.

Lampley’s case was initially dismissed by the Missouri Human Rights Commission, which claimed that he has no standing because its Human Rights Act doesn’t enumerate protections on the basis of sexual orientation. Numerous attempts to add that identity category in the state codes have stalled in the legislature.

The Court of Appeals effectively reversed the commission’s decision.

Gabbert wrote that the ruling “simply recognizes the manifold ways sex discrimination manifests itself,” citing the Supreme Court’s 1989 ruling in Price Waterhouse v. Hopkins as precedent. SCOTUS ruled that a female executive could claim discrimination on the basis of sex stereotyping if she was a victim of bias due to having an “unfeminine” appearance.

Missouri judges claimed that the state’s Human Rights Commission is compelled by law to issue Lampley a right-to-sue letter, one that will allow his case to move forward.

Advocates in Missouri championed the ruling, the first-of-its kind in the Show-Me State.

“This is an important step forward to protecting LGBTQ Missourians from discrimination in the workplace,” said Steph Perkins, executive director of the LGBTQ group PROMO, in a press release. “We are grateful to see that the courts are recognizing LGBT discrimination for what it isunlawful and wrong.”

Missouri is one of 30 states that lack statewide protections on the basis of gender identity and sexual orientation. Others include Arizona, Michigan, Pennsylvania, and Texas.

Photography: Getty Images / Raymond Boyd