“Our members have spoken loud and clear—Costco must deliver a fair contract, or they’ll be held accountable,” Teamsters General President Sean M. O’Brien said in the statement. “From Day One, we’ve told Costco that our members won’t work a day past January 31 without a historic, industry-leading agreement.”

Prior to the vote, which 85% of members supported, workers organized practice pickets across the country, including actions last week in Hayward, California; Sumner, Washington; and Long Island, New York.

While Costco is known for paying its employees higher wages than its competitors, the union is accusing the company of not sharing its recent success with workers.

“Costco claims to treat workers better than the competition, but right now, it’s failing to live up to that reputation,” Tom Erickson, director of the Teamsters Warehouse Division, said.

• Costco recently reported that net sales in December were up 9.9% from the year before.

Business as usual: In an earnings call last month, Costco President and CEO Ron Vachris told shareholders that the company is focused on a “fair and timely process for getting to an agreement with the Teamsters,” and emphasized that “we have a 40-year track record of dealing fairly with the Teamsters union, and really nothing has changed about that.”

The Teamsters have lately shown themselves willing to take on some of the biggest retailers. At the peak of the holiday season in December, the union authorized a strike of Amazon that lasted until December 24. Workers formed picket lines at hundreds of fulfillment centers, but went on strike at just nine locations.

While Amazon doesn’t usually acknowledge the union, the Teamsters claim to represent nearly 10,000 workers at the e-commerce giant.

This report was originally published by Retail Brew.