The strike authorization vote passed with an 85% margin, the union said. Investors didn’t seem concerned, however. Costco stock was up 1% to $952.28 in midmorning trading Tuesda

Members of the Teamsters union have authorized a strike against Costco on February 1 unless they reach a deal with the warehouse retailer before the current contract expires 31.

More than 18,000 Costco workers will be walking picket lines in less than two weeks if a labor dispute over wages and benefits is not resolved, according to the Teamsters union. Members voted by an 85% margin to authorize a strike when their current contract expires on Jan. 31, the union announced on Sunday.