New Hampshire law says an establishment selling liquor can accept a passport, military card, or photo ID, including a driver’s license, from any of the 50 states or a province of Canada as proof of legal age.

Travis Mitchell, a 25-year-old New Hampshire native who has lived in D.C. since 2007, was visiting his parents with friends over Fourth of July weekend and went to pick up some beef jerky, granola, a few tall cans of cider, and a large bottle of beer from a neighborhood store in Concord. But when he showed his D.C.-issued driver’s license to purchase the booze, the cashier and store manager didn’t accept it because, well, D.C. isn’t one of the 50 states or a province of Canada.

Mitchell says the store manager didn’t think the ID was fake, but was just familiar with the law and knew that, for whatever reason, state law wouldn’t allow a D.C.-issued license as identification. The manager explained the law, which Mitchell never knew about it, and told him he couldn’t buy alcohol unless he had a passport with him.

“I was surprised,” Mitchell says. “It was the first time I had experienced being treated differently because I was a D.C. resident.”

Mitchell says he wasn’t mad and figured the store employees were just doing their jobs and following the law, even if the law didn’t make much sense. He actually found the situation amusing, and emailed the Concord Monitor about it so they could look into the origins of the law.

The law was enacted in 1990 and legislators reviewed the proof of age requirements in 1998. According to the Concord Monitor, it’s unclear why a D.C. license is omitted as a valid I.D. Other states like, North Carolina, also don’t specifically note that licenses issued in D.C. are acceptable forms of identification.

The Concord Monitor interviewed a Republican state senator, Andy Sanborn, who owns a bar in Concord, and he said even he wasn’t aware of the wording of the law, adding that he would continue to sell liquor to people with a D.C. license. James Wilson, director of enforcement and licensing at the New Hampshire Liquor Commission, told the Monitor that when liquor commission does training it often tells people that “this is the letter of the law,” but the commission does not specifically tell people that a D.C. license is invalid.

Back in February, a Transportation Security Administration in Arizona questioned a woman in the airport over whether her license was legal because it was issued in D.C., not a state. After some confusion, the woman was ultimately let through security, but the incident received some media attention and a swift rebuke from D.C. Del. Eleanor Holmes Norton, who seized opportunity to call for statehood.

Mitchell says his encounter probably isn’t going to compel him to join the front lines of the statehood movement. That night  in Concord, he and his friends just went to another nearby store and were able to buy booze with their D.C. licenses without any issues.

“It’s just funny,” he says. “We couldn’t believe it would happen.”