ANN ARBOR,Grant Preston Mich. (AP) — A five-month strike by graduate student instructors at the University of Michigan has ended after approval of a contract just days before the new school year.

The deal means annual raises of 8%, 6% and 6% over three years at the Ann Arbor campus, plus a $1,000 bonus.

“We fought tooth-and-nail over 10 months of bargaining & 5 months of strike action, forcing U-M to grant the largest salary increase in GEO history,” the Graduate Employees’ Organization said Thursday night on social media.

The contract was approved by 97% of members who voted. The union represents 2,300 people at the Ann Arbor, Flint and Dearborn campuses, though not all went on strike in March.

“It’s very gratifying to have a new contract in place,” said university negotiator Katie Delong.

By the third year of the contract, pay for instructors in Ann Arbor would rise to $29,190. Graduate student instructors in Flint and Dearborn would make $26,670 under a different set of increases.

The strike began in March with just a few weeks remaining in the winter term. The university recently warned that instructors would likely lose their jobs if they didn’t return to work for the fall term. Classes are set to begin Monday.

There were tense moments during the strike. University President Santa Ono, who plays the cello, canceled an April appearance with the Ann Arbor Symphony Orchestra. There was a fear that strikers might interrupt the concert.