Striking machinists accepted a new contract raising wages by 39 percent, but enduring bitterness will complicate Boeing’s efforts to rebuild its battered corporate culture and flawed production process.

The Boeing Company and the International Association of Machinists and Aerospace Workers union agreed to a new contract to officially end the 7-week strike.

The approved contract offer includes a 38% raise over the next four years, a ratification bonus of $12,000 and expanded 401(k) contributions.