Amazon Labor Union (ALU) members voted to affiliate with the International Brotherhood of Teamsters in a move they hope will bring new life to a yearslong struggle to secure union contracts for Amazon warehouse workers.

Amazon has tried to block various efforts to unionize across different branches of the company since at least 2000, but the movement to unionize warehouse workers only gained steam in the past few years. The Teamsters, founded in 1903, is one of the biggest labor unions in the US.

Employees at the Staten Island warehouse, known as JFK8, became the first Amazon workers to vote to unionize in 2022. They still don’t have a contract, as the union struggles to get Amazon to the bargaining table. Union members at JFK8 approved an affiliation agreement with the Teamsters after three days of voting, the groups announced today.

That means that a new ALU-International Brotherhood of Teamsters (IBT) Local 1 will represent some 5,500 Amazon warehouse workers at JFK8. If any other Amazon warehouses in New York City vote to unionize, Local 1 would have jurisdiction for their workers as well.

Staten Island union organizers now have access to more financial resources thanks to the partnership. The Teamsters, meanwhile, have been trying to unionize Amazon warehouse workers across the US.

“On behalf of the Amazon Labor Union, I’m proud of our members choosing a path to victory. We’re now stronger than ever before,” ALU president Chris Smalls said in a press release. “Having the support of 1.3 million Teamsters to take on Amazon gives us tremendous worker power and the opportunities to demand better conditions for our members and, most importantly, to secure a contract at JFK8.”

JFK8 workers in particular have faced mounting obstacles since its historic vote to unionize in 2022. Amazon quickly objected to the results of the election and has yet to agree to bargain with the ALU, The New York Times reports. Amazon didn’t immediately respond to a request for comment from The Verge.

Amazon workers at the company’s biggest US air cargo hub, KCVG in Kentucky, also voted to affiliate with the Teamsters earlier this month. But so far, JFK8 is still the only Amazon warehouse to have successfully voted to unionize.

The Teamsters secured a win with UPS warehouse workers in a new contract last year.

“The Teamsters set the standard with our agreement protecting 340,000 UPS warehouse workers and drivers in this industry. You can be certain that we will hold Amazon to these same standards, and not the other way around,” Teamsters general president Sean O’Brien said in the press release.