Wisconsin employees of video game publisher Activision Blizzard, developers of the “Call of Duty” franchise, have voted to unionize.

Calling themselves the Game Workers Alliance, the quality assurance testers voted 19-3 on May 23 to form the labor union, a first for a larger U.S.-based video gaming company.

The newly unionized workers are from Activision Blizzard’s Raven Software, located in Middleton, Wisconsin. The Milwaukee office of the Labor Relations Board counted the votes, and the new union will become part of the Communications Workers of America.

“We respect and believe in the right of all employees to decide whether or not to support or vote for a union. We believe that an important decision that will impact the entire Raven Software studio of roughly 350 people should not be made by 19 Raven employees,” Activision officials said in a statement published by Reuters.

The game publisher, headquartered in Santa Monica, California, is currently being purchased by Microsoft for $68.7 billion. The announcement by Microsoft to acquire Activision Blizzard was made in January.

Microsoft stated they would not interfere with unionization efforts. The National Labor Relations Board (NLRB) accused Activision of interfering with employee union efforts. According to a Bloomberg report, the NLRB is asking Activision to settle, or they will file a complaint.

On Tuesday, Activision Blizzard Inc. shares dropped 0.22% to $77.03. The stock closed $22.43 below its 52-week high of $99.46 in June last year. Meanwhile, Microsoft Corp. stock also fell 0.40% to $259.62, MarketWatch reported.