Quality assurance workers at Activision Blizzard studio Raven Software have voted to unionize, becoming the first group to do so at a major gaming publisher in North America. The National Labor Relations board counted the ballots on Monday — 19 workers voted in favor of the union and three voted against. Two ballots were challenged, though they weren’t sufficient enough to affect the result. There were 28 eligible voters and no void ballots.

The NRLB notes that the parties can file objections by May 31st. If it doesn’t receive any by then the agency will certify the results and Raven will need to start bargaining with the union in good faith.

In December, 60 workers (including contractors and full-time employees) at the Call of Duty support studio went on strike after it laid off 12 QA testers. They demanded that the company hire those workers back. The strike ended the following month, but not before the QA workers announced plans to unionize with the Communication Workers of America (CWA). Once they were back at work, Raven split them up among various departments, in an apparent attempt to make their unionization efforts more difficult.

The workers asked Activision Blizzard to voluntarily recognize their union, which they called the Game Workers Alliance. However, the company declined to do so. Last month, the National Labor Relations Board gave the workers the go-ahead to hold a union election.

“Activision did everything it could, including breaking the law, to try to prevent the Raven QA workers from forming their union. It didn’t work, and we are thrilled to welcome them as CWA members,” CWA secretary-treasurer Sara Steffens said in a statement. “Quality assurance workers at Raven Software are bringing much-needed change to Activision and to the video game industry. At this critical time for the company and its employees, these workers will soon have an enforceable union contract and a voice on the job.” 

Activision Blizzard has been accused of union busting. Last July, it hired the law firm WilmerHale, which has reportedly engaged in efforts to stamp out union drives at Amazon and other companies, to review its human resources policies. It also shared anti-union messaging in company Slack channels.

In April, Activision Blizzard said it was hiring 1,100 QA workers on a full-time basis, increasing their pay in many cases and providing benefits. However, it claimed the Raven QA workers were not eligible “due to legal obligations under the National Labor Relations Act.”

Earlier on Monday, the NRLB determined that Activision Blizzard violated the National Labor Relations Act. It claimed the company threatened employees who sought to organize and imposed an ‘overbroad social media policy.’

Activision Blizzard is being bought by Microsoft for $68.7 billion, pending regulatory approval. Microsoft has said it “will not stand in the way if Activision Blizzard recognizes a union.” The company told Axios in March that it “respects Activision Blizzard employees’ right to choose whether to be represented by a labor organization and we will honor those decisions.”

In December, workers at indie studio Vodeo Workers formed the first video game union in the US. Management voluntarily recognized Vodeo Workers United. Workers at studios outside of North America have unionized as well, including at Paradox Interactive in Sweden and Japanese–Korean publisher Nexon. Meanwhile, QA workers at BioWare contractor Keywords Studios in Edmonton, Alberta are attempting to unionize.

The Game Workers Alliance provided the following statement to Engadget:

Five months ago, we formed the Game Workers Alliance-CWA on the principles of solidarity, sustainability, transparency, equity, and diversity. Activision Blizzard worked tirelessly to undermine our efforts to establish our union, but we persevered. Now that we’ve won our election, it is our duty to protect these foundational values on which our union stands. Our biggest hope is that our union serves as inspiration for the growing movement of workers organizing at video game studios to create better games and build workplaces that reflect our values and empower all of us. We look forward to working with management to positively shape our working conditions and the future of Activision Blizzard through a strong union contract.