38-year-old Ibrahimovic previously played for the Rossoneri from 2010-2012, scoring 56 goals and winning the 2011 Serie A title under Massimiliano Allegri
Veteran striker Zlatan Ibrahimovic has signed a one-year contract extension with AC Milan, the Italian giants announced on Monday.
The former Swedish international, who turns 39 in October, rejoined Milan in January and will stay at the San Siro until the end of June 2021.
"Today (Monday), Zlatan Ibrahimovic rejoined his teammates and coach Stefano Pioli at Milanello Sports Center, where he took part in his first training session of the season," the club said in a statement.
According to Italian media reports, Ibrahimovic has agreed a seven-million-euro ($8.35-million) annual salary with Milan.
He helped Pioli's side bounce back from a poor first half of last season, scoring 11 goals in 20 games in all competitions to help fire the seven-time European champions to Europa League qualification.
Ibrahimovic said at the weekend that he "wanted to help the club return to where they belong".
"For six months, we have done great things but we have not won anything. We must continue and do the same," he said in a video.
The 38-year-old previously played for the Rossoneri from 2010-2012, scoring 56 goals and winning the 2011 Serie A title under Massimiliano Allegri.
It had been widely expected that 'Ibra' would sign a new deal and he will take the number 11 shirt, having played as Milan's number 21 last term.
OFFICIAL: Zlatan signs a one-year contract renewal with AC Milan 🦁 pic.twitter.com/JVmsCasNV9— B/R Football (@brfootball) August 31, 2020
He had returned from American MLS outfit Los Angeles Galaxy on a six-month contract with an optional extra year.
Milan finished last season with a 12-match unbeaten streak in Serie A to grab a sixth-place finish, although they still fell short of returning to the Champions League for the first time since 2014.
Ibrahimovic has also played for Juventus and Inter Milan in Italy during his illustrious career and starred for Paris Saint-Germain in France and Manchester United in the Premier League.
He won four Ligue 1 titles with PSG during a four-year spell in which he became the club's record goalscorer, a mantle since taken by Edinson Cavani.
'Ibra' has also lifted the La Liga trophy with Barcelona in 2010, three league titles with Inter and two Eredivisie crowns while at Ajax.