(CNN) -- Books, notebooks, pens and a fully loaded, semi-automatic gun.
The first few items are standard classroom material, but not the last -- which is why a 15-year-old boy at Toronto's Jarvis Collegiate Institute ended up under arrest, according to police.
Officers went into the teenager's classroom around 1:15 p.m. Friday and arrested him on charges that included unauthorized possession of a firearm, careless storage of ammunition and carrying a concealed weapons.
He is set to appear in court at Toronto's Old City Hall on Saturday morning, police said.
According to its website, Jarvis Collegiate Institute is the oldest secondary school in Toronto, having been founded in 1807.
CNN's Greg Botelho and Kevin Conlon contributed to this report.