According to The Athletic‘s Shams Charania, the extension does not include any player or team options.
ESPN’s Adrian Wojnarowski was the first to report the deal.
The team had until Oct. 21 to agree to a new deal, otherwise he would’ve become a restricted free agent in the summer of 2020.
Siakam, 25, had a breakout 2018-19 campaign, capturing the NBA’s Most Improved Player Award after putting up 16.9 points, 6.9 rebounds and 3.1 assists on 54.9 per cent shooting from the field and 36.9 from three.
The 2016 first-round pick (27th overall) raised his game even further in the playoffs, averaging 19.0 points and 7.1 rebounds, as the Raptors captured their first title in franchise history.
The season prior, his second in the league, Siakam recorded averages of 7.3 points, 4.5 rebounds and 2.0 assists on 50.8 per cent shooting and 22 per cent from beyond the arc.