Dining hall workers at Harvard University began a strike early Wednesday after the union employees and university representatives failed to reach an agreement over a new contract.

The strike—the first one by Harvard employees since 1983, and the first ever during the academic year, according to union and school officials—was announced after mediator-led negotiations broke down between the school and the food service staffers, members of UNITE HERE Local 26. Their prior contract was originally set to expire in June, but had been extended through September.

The union says it represents about 750 food service workers across Harvard.

Workers convened at more than a dozen picket locations on campus Wednesday morning, joined by some students. Meal service was modified at some dining halls as a result of the strike.

“It’s Harvard that has put us in this situation,” said Brian Lang, president of Local 26. “And it’s Harvard that has the means to fix this situation. It’s just that the administration has not chosen to do so yet.”