Harvard University was tied up for much of October with a strike by the school's dining hall workers and another strike may take over the Cambridge campus soon.

Janitors at the university voted on Thursday to authorize their union, 32BJ SEIU, to call for a strike if they don't reach an agreement when their contracts expire on Nov. 15.

“The janitors who help to keep Harvard at the top are ready to do what it takes to protect their families and their communities,” said Roxana Rivera, vice president of 32BJ SEIU, in a statement.

The same union previously represented Tufts University janitor workers, who were able to reach an agreement mere hours before their contract expired earlier this month, avoiding a strike.

Negotiations by the union and Harvard University began on Oct. 7 for a contract that covers more than 700 custodians. The workers are asking for wages that correlate to the rising cost of living in the Boston area and for paths to more full-time jobs. 

"Far too often employers deliberately part-time what could be decent jobs to avoid their responsibility of paying health care for their workers," the union said in a statement. "When this happens, workers either lose income or take on multiple part-time jobs and spend less time with their families and in their communities."

Harvard has $44.6 billion in total net assets, the union notes.