In a win for social justice advocates in the workplace, the National Labor Relations Board ruled Wednesday that big-box retailer Home Depot broke the law by requiring workers to remove “Black Lives Matter” insignia from their uniforms and punishing one for refusing to do so.

The board’s majority wrote in their decision that employees sporting the letters “BLM” on their attire as they pushed management on race issues amounted to “protected concerted activity,” and was therefore shielded by the law. They ordered Home Depot to offer reinstatement and back pay to a worker who’d resigned rather than remove their BLM marking.

The NLRB enforces collective bargaining law on private-sector employers, and its five-member board in Washington serves as a high court for resolving labor disputes. (At the moment, there are only four members.) The BLM ruling falls in line with the board’s more progressive reading of the law under a Democratic majority shaped by President Joe Biden.

The board’s lone Republican member dissented.

According to the NLRB decision, a Home Depot manager had told the workers they had to take off their BLM insignia because it conflicted with the company’s dress code. One employee was told that if they wore “BLM” on their uniforms, then management would have to let others wear swastikas, according to trial testimony.

A Home Depot spokesperson said the company disagrees with the decision.

“The Home Depot is fully committed to diversity and respect for all people. We don’t tolerate any kind of workplace harassment or discrimination,” the spokesperson said.

The company declined to say whether it plans to appeal the ruling to federal court.

The labor board’s decision reversed an earlier ruling by an administrative law judge who heard the case and determined that the workers’ BLM protest wasn’t protected because it wasn’t specifically tied to issues at their workplace. Instead, the judge found, Black Lives Matter served as a “political umbrella for societal concerns,” rather than for a particular work grievance.

“We reject that reasoning,” the board members wrote. “Neither the origins of BLM messaging, nor its primary use, dictate how the BLM marking may be used or understood in a particular workplace context (or, indeed, in a broader setting).”

The Home Depot dispute arose at a store in the Minneapolis suburb of New Brighton, Minnesota, in the months following the 2020 murder of George Floyd, a Black man, by Minneapolis police officers. Floyd’s death sparked Black Lives Matter protests around the country.

Workers at the New Brighton store were dealing with what they said were several racist incidents at the time. One co-worker had exhibited “racial bias toward customers and fellow employees,” the NLRB decision states, to the point where other workers would “intercept” customers of color so they wouldn’t have to deal with the employee in question. Black History Month displays in the store had been vandalized, and some workers felt that managers didn’t sufficiently address what had happened.

The worker who was unlawfully punished, Antonio Morales, pressed management on the vandalism incident and wound up getting reprimanded for wearing “BLM” marked on a work apron.

“This was the first time that a manager or supervisor had said anything about the BLM marking even though Morales had worn it continuously for the prior 5 months,” the decision states.

The Home Depot case is one of several before the board involving racial justice messages at work.

In December, one of the agency’s administrative law judges ruled that Whole Foods did not break the law when it told workers to remove their Black Lives Matter gear, saying the protest wasn’t directly tied to their working conditions.

“The fact that BLM may be a movement of great significance to African Americans, and that its goals are valid, does not mean that a rule prohibiting the displaying of such messages at work is ‘racist,’ as some employees implied,” the judge wrote.

That case is on appeal before the board in Washington.