Georgia Tech will pay a $500,000 civil penalty after a U.S. Department of Justice investigation determined that career opportunities posted on a school-run job board unlawfully excluded students who weren’t U.S. citizens.

The federal agency, which announced the settlement last week, said third-party employers paid the school to post ads linked to career fairs that violated the anti-discrimination provision of the Immigration and Nationality Act. The ads restricted or discouraged applications from certain non-U.S. citizens, such as lawful permanent residents, refugees and those granted asylum who the department said stand on equal footing with citizens for hiring purposes.

“Our nation’s higher education institutions must ensure that their job recruiting platforms don’t promote, facilitate or enable unlawful citizenship discrimination,” said Assistant Attorney General Kristen Clarke of the department’s Civil Rights Division, in a written statement. “The Justice Department will vigorously enforce the Immigration and Nationality Act’s nondiscrimination mandate to ensure that college students are treated fairly and have an equal opportunity to compete for internships and jobs.”

Georgia Tech spokesman Blair Meeks, in a written statement, said the school cooperated with the investigation and “does not intentionally discriminate against students in its career services offerings.”

The school has begun to make changes to address concerns about career fairs and the job recruiting services used by Georgia Tech.

“We will continue to support our students so that they are positioned to launch and sustain satisfying and successful careers that make a meaningful contribution to society,” the statement said.

The Justice Department notified Georgia Tech three years ago that it had begun to investigate the situation after a student who was a lawful permanent resident filed a discrimination complaint. The student alleged a bank advertised an internship for only U.S. citizens on Georgia Tech’s career website, according to the federal agency.

The resulting investigation revealed additional discriminatory ads and also found that Georgia Tech routinely allowed employers to block students who weren’t U.S. citizens from applying to jobs through the school’s platform, the agency said.

Georgia Tech’s penalty comes on top of more than $1.6 million in previously announced civil penalties paid by 30 employers who advertised jobs on the school’s site. Those employers include financial, technology and accounting firms as well as major corporations such as American Express Co., Honeywell International Inc., Capital One Bank and Walmart.

As part of the settlement, Georgia Tech must change its recruiting practices and provide three years of training to ensure its career services employees understand the law.