A Green Bay Packers fan is suing the Bears over a dress code he says prevented him from wearing his Packers gear on the field during a special game-day event for Bears season-ticket holders.

Beckman — a Wisconsin native who has season tickets to his beloved team’s games, as well as to Bears games — claims the dress code violates his First Amendment rights.

The Bears launched the “STH Experience,” short for “season ticket holder experience,” in 2014. The program offers points to season ticket holders that can be cashed in so they can be on the Soldier Field turf before certain games and attend other exclusive events.

There’s a catch, though: The fans must be in Bears gear.

And Beckman, who is representing himself in his federal lawsuit, wouldn’t be caught dead wearing Bears garb on a Packers game day. The main reason he has Bears season tickets is so he can make sure he has tickets to both Packers-Bears games each season.

During the 2014 and 2015 seasons, Beckman went to a “pregame warm-up field experience” at Soldier Field decked out in his Packers gear without any issue. He was expecting to do the same last year, but six days before the game, he received an email with a list of rules, including one that said: “No opposing team gear will be allowed,” according to his lawsuit.

After exchanging emails with the Bears, Beckman knew he’d be denied entry if he wore his Packers jersey. He did anyway and, as expected, wasn’t let on the field.

Beckman appealed the matter to NFL Commissioner Roger Goodell but received no reply, according to the lawsuit.

So Beckman decided to take his case to court, filing his lawsuit on Friday. He’s not asking for money; he wants the Bears and NFL to allow fans to wear what they want during fan experiences.

A Bears spokesman said the team doesn’t comment on legal matters.

Beckman said that he has nothing but respect for the Bears and their fans.

“I enjoy going to Chicago to watch the Bears play the Packers every year in Soldier Field,” he said Monday in a phone interview. “I think the Bears are being disrespectful to their fans by not letting them wear what they want.”

He also said that he attends other Bears season ticket holder events.

“When I attend other Bears events, I’m very careful to not wear Packers gear unless it’s the day of a game,” Beckman said. “I don’t want to be in people’s faces. But when I go to games, I like to wear my [Packers] jersey. It’s part of the experience.”