Boeing technical workers have approved a new four-year contract after a nearly year-long negotiation. The Society of Professional Engineering Employees in Aerospace (SPEEA)-represented workers were told by union negotiators that a second rejection would likely result in a strike.

“Union members were voting on a contract offer that was identical to the offer the 7,191 technical workers narrowly rejected and the larger professional unit of engineers narrowly accepted on Feb. 19,” SPEEA said in a statement. “While engineers and technical workers bargain at the same time, the contracts are separate and independent agreements.”

The new contract includes 5% annual salary increase pools plus an increase to retirement benefits, but no increases to employees for medical coverage, SPEEA said. The union noted that the end of the new contract will mark—for both technical workers and engineers—eight straight years of 5% salary increase pools with guaranteed minimum wage increases each contract year.

Boeing’s negotiations with SPEEA began in April 2012.