Since that time, approximately 123,000 same-sex marriages have taken place, according to the Gallup Organization, and there are now about 491,000 such marriages in the U.S.

The only problem is that it’s still legal to fire LGBT employees in 28 states where such workers aren’t covered by state laws that protect various minorities from discrimination on the job, as well as in housing and public accommodations.

That discrepancy has business owners worried, particularly those who do business in states that lack protections. In fact, roughly three–quarters of business owners say they expect to see discrimination claims by LGBT workers rise over the next year, compared to 31% who had such worries in 2015. That’s according to an executive employer survey report published by the employment law firm Littler Mendelson earlier in July. Littler polled 844 executives and professionals primarily at small and mid-sized businesses in the spring.

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Business owners should pay attention. Soon after last year’s SCOTUS ruling, the Equal Employment Opportunity Commission (EEOC), the federal regulating body charged with enforcing the anti-discrimination statutes of the 1964 Civil Rights Act, issued guidance suggesting the act’s Title VII provision would extend to provide workplace protections based on sexual orientation and gender expression.

Originally, Title VII prohibited employment discrimination based on race, color, religion, sex and national origin. The provision was expanded in 1990 to include people with disabilities, following the passage of the Americans with Disabilities Act.

While there may ultimately be court challenges, the EEOC also has the authority to interpret new laws not only by adding protected groups, but also through enforcement of existing guidelines. And it can use the legal argument that sexual orientation and gender expression fit into the prohibition against discrimination based on sex, says Mark T. Phillis, a Littler Mendelson shareholder and co-chair of its diversity and inclusion council.

Here’s a list of some things that EEOC says are prohibited:

— Failing to hire an applicant because she is a transgender woman.

— Firing an employee because he is planning or has made a gender transition.

— Denying an employee equal access to a common restroom corresponding to the employee’s gender identity.

— Harassing an employee because of a gender transition, such as by intentionally and persistently failing to use the name and gender pronoun that correspond to the gender identity with which the employee identifies, and which the employee has communicated to management and employees.

— Denying an employee a promotion because he is gay or straight.

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— Discriminating in terms, conditions, or privileges of employment, such as providing a lower salary to an employee because of sexual orientation, or denying spousal health insurance benefits to a female employee because her legal spouse is a woman, while providing spousal health insurance to a male employee whose legal spouse is a woman.

— Harassing an employee because of his or her sexual orientation, for example, by derogatory terms, sexually oriented comments, or disparaging remarks for associating with a person of the same or opposite sex.

— Discriminating against or harassing an employee because of his or her sexual orientation or gender identity, in combination with another unlawful reason, for example, on the basis of transgender status and race, or sexual orientation and disability.

The expansion is not likely to pose difficulties for businesses operating in the 22 states and more than 200 municipalities and counties that already have inclusive anti-discrimination laws, but it could be an issue for businesses operating in places without those laws, Phillis says.

Here are four things Littler recommends business owners should do right now to ward off discrimination lawsuits:

— Review your equal employment opportunity and anti-harassment policies and consider adding a commitment not to discriminate against employees based on sexual orientation, and gender identity or expression.

— Make sure your anti-harassment training incorporates scenarios clarifying that discrimination against LGBT employees is unacceptable.

— Take a look at your employee handbook policies and benefits offerings and make sure they use gender-neutral language, rather than gender-specific terms. One example would be “spouse,” rather than “husband” or “wife”.

— Examine health insurance offerings. Make sure they are consistent with recent regulations, such as the one passed in 2016 by U.S. Department of Health and Human Services, which generally prohibit discrimination in healthcare offerings related to gender transition.

Taken together, these recommendations could help ward off potential lawsuits. More important, they’ll send a strong signal to your employees—and potential new hires–that you’re serious about eliminating discrimination in the workplace.

“By making it clear that discrimination against LGBT employees is prohibited, employers will better position themselves to recruit not only the estimated three percent of the population that identifies as LGBT, but also other candidates, particularly millennials, who expect to work in a diverse and inclusive workplace,” Phillis said in emailed comments.