Striking Boeing defense workers in Missouri voted Friday against the company’s latest offer of a modified contract deal, according to the union representing the workers.

More than 3,000 workers in the St. Louis area will remain on strike, the first walkout in almost three decades.

“Boeing’s modified offer did not include a sufficient signing bonus relative to what other Boeing workers have received, or a raise in 401(k) benefits,” a statement from the International Association of Machinists and Aerospace Workers read. “The democratic vote underscores the determination of approximately 3,200 IAM Union members to continue their stand together until their voices are heard.”

The union had said it reached a tentative five-year agreement with Boeing on Wednesday, with better wages and a signing bonus, and set a vote on the deal for Friday.

The deal that workers rejected included 45% average wage growth, among other things. The local chapter of the union, IAM 837said it would bring the average wage from $75,000 to $109,000.

“Our members in St. Louis have once again shown that they will not settle for Boeing’s half-measures,” IAM International President Brian Bryant said in a statement. “Boeing must start listening to its employees and come back to the table with a meaningful offer that respects the sacrifices and skill of these workers.”

Boeing has said it is hiring more workers to replace those who are on strike to meet rising demand.

Boeing Air Dominance Vice President Dan Gillian said in a statement that no further talks are scheduled between Boeing and the striking workers, and that the company is “disappointed.”

“We’ve made clear the overall economic framework of our offer will not change, but we have consistently adjusted the offer based on employee and union feedback to better address their concerns,” Gillian said. “We will continue to execute our contingency plan, including hiring permanent replacement workers, as we maintain support for our customers.”

The striking workers mostly assemble and maintain F-15 fighter jets and missile systems, according to the union. The employees went on strike in early August and turned down a previous offer, which included 20% general wage increases and a $5,000 signing bonus, among other improvements.