An 18-year-old lesbian high school student has filed a discrimination complaint against Buffalo Wild Wings, alleging a server forced her to prove her gender while she was in the women’s restroom earlier this year, according to the advocacy group Gender Justice.

KTLA reports that the incident took place in April at a Buffalo Wild Wings in Owatonna, Minnesota, about an hour south of Minneapolis. Gender Justice, which filed the complaint on the teen’s behalf, said the server followed Gerika Mudra into the restroom, banged on the stall door, and said, “This is a woman’s restroom. The man needs to get out of here.”

Mudra, who is not transgender, said she left the stall and told the server she was female, but was again told she needed to leave.

“The employee blocked her from leaving until Mudra unzipped her hoodie to show she had breasts,” the organization said in a news release. “Only then did the server relent.”

Mudra told NBC News she has faced similar experiences in women’s restrooms before, though usually when she states she is female, she is left alone. This time, she said, the encounter made her feel extremely uncomfortable.

“After that, I just don’t like going to public restrooms. I just hold it in,” she explained.

The complaint, filed with the Minnesota Department of Human Rights, alleges the incident violated the state’s Human Rights Act, which prohibits discrimination based on gender identity and sexual orientation in public accommodations. Minnesota is one of 21 states, plus Washington, D.C., with such protections.

“We know Gerika was targeted because of how she looks,” Shauna Otterness, the teen’s stepmother, said. “She didn’t do anything wrong. She just didn’t fit what that server thought a girl should look like. This shouldn’t be normal. We can do better, and we have to.”