University stabber to spend more time behind bars in Ontario after judge corrects math [Video]

The man behind a mass stabbing in a University of Waterloo gender studies class will have to stay behind bars longer after an Ontario judge recalculated how much to deduct for the time he had already spent in custody.

Geovanny Villalba-Aleman was sentenced last month to 11 years in prison for what Ontario Court Justice Frances Brennan deemed a “particularly grave” hate crime targeting the LGBTQ+ community.

At the time, Brennan said Villalba-Aleman would be given credit for 1,254 days of pre-sentence custody, leaving him to serve nearly seven years and seven months behind bars.

Federal prosecutors confirmed that Brennan corrected what she deemed a mathematical error on Monday, saying he should instead get credit for 941 days.

That would leave him with about eight years and five months to serve.

Villalba-Aleman, 25, had pleaded guilty to two counts of aggravated assault, one count of assault with a weapon and …