The grocery chain’s store in Philadelphia becomes the first to join a union, where workers hope to expand organizing to other outlets and across the Amazon empire.

The union win, at a Philadelphia store where workers are seeking higher wages, comes as Amazon is also fighting organizing efforts among some warehouse employees and delivery drivers.

Some 300 workers at an Amazon-owned Whole Foods store in Philadelphia have voted to unionize, mirroring a pro-union shift in public opinion, according to Gallup.