Election officials in St. Louis are making sure the city's voting machines are working properly ahead of the General Municipal Election on April 4, 2017. That's when St. Louis will choose a new mayor and decide the fate of a professional soccer stadium.

Officials put all 342 electronic machines through what's called a logic and accuracy test this week, wrapping up with the final machines on Friday. It's a required test to make sure the machines work the way they were designed to work so that they'll be good to go at all 114 polling places.

"So we can be sure of that, the voters can be sure of that, and everything can go smoothly on Election Day," Republican Tabulation Supervisor Matt Zakibe said. "We run a set of ballots through each machine with a predetermined outcome. We then take the memory cards from inside the machines and upload them to our server and we make sure the results match what we expected them to match."

Zakibe says, each election, there tends to be a few physical problems with the machines, like a broken printer or motor, but they've never come across a machine that counts votes incorrectly. Even so, the tests are important.

"We're trying to make sure that there's no even perceived chance of some sort of irregularities on Election Day," Zakibe said.