The rank and file may have ratified the contract, but the president of the Chicago Teachers Union said the issue with school closings is her next fight.
"I've still got my boxing gloves," Karen Lewis told reporters Thursday.
Teachers remain worried that Chicago Public Schools officials are secretly planning to close up to 100 schools in an effort to save money.
There is even a growing number of Chicago aldermen who are calling for hearings before Mayor Rahm Emanuel takes action.
"CPS has been doing school closings for 15 years, and for them to try and say that school closings is a way to pay for the contract is not only ridiculous, it's not true," said Lewis.
District officials haven't laid out specific plans on how to fund the $295 million contract but hinted the negotiations offered a new spirit of cooperation.
"It's a great example for our students that even if you start far apart, if you work hard at it you work hard enough at it you can actually come to common ground," said Chicago Board of Education President David Vitale.
Teachers, paraprofessionals and school clinicians voted Tuesday on the tentative contract that ended Chicago's first teacher strike in 25 years. The results of that vote were released late Wednesday and showed an overwhelming majority of staffers -- 79.1 percent of the ballots cast -- were in favor of the contract.
It still requires approval from the Board of Education, but that doesn't appear to be in jeopardy given Vitale's remarks.
Thousands of teachers in the nation's third-largest school district walked off the job on Sept. 10 after more than a year of slow, contentious negotiations over salary, health benefits and job security.
The deal will give teachers an average pay raise of 17.6 percent over four years if the three-year contract is extended an extra year. The pay increases would cost an extra $74 million a year, the district has said. Chicago teachers make an average of about $76,000 annually, according to the school district.
Students were kept out of classes for seven days before CTU's members voted to end the work stoppage.