More than 2,000 test ballots were counted as though they were ballots cast by voters during Cambridge’s election last week, an error officials blamed on the vendor overseeing the city’s election system.

As a result, the unofficial tallies posted on the night of the election included thousands of extra votes — more than 1,300 in the race for seats on the School Committee, more than 600 in the race for City Council and more than 150 for a ballot question. When officials recalculated the votes, the makeup of the School Committee was changed.

The unofficial results released in the hours after polls closed showed Eugenia Schraa Huh had defeated incumbent David J. Weinstein for the fifth and final seat on the School Committee. But with the test ballots removed, the results showed that Weinstein had actually hung on to his seat.

The updated results did not change the outcome of the City Council race or the result of the ballot question.

It took two days for city officials to publicly announce the error and the new results.

“The Cambridge Election Commission conducts rigorous and mandatory prequalified testing for every election,“ officials said in a statement. ”Through its proactive auditing process, the Election Commission determined that ballots used for testing were not fully cleared from the Election Management System by the vendor in advance of the Municipal Election on November 4, 2025."

Jeremy Warnick, a spokesman for the city, told The Boston Globe that the vendor had assured officials “steps are being taken to retrain their staff to ensure this mistake does not happen again.”