“I love the team and the people at this club,” he told the club website.
“I can’t wait for the future and to see what we can achieve as a team.”
Director of rugby George Skivington added: “Mati is a very humble, hard-working rugby player and a big leader too.
“A player of his calibre is always going to have other options available to him, so we’re delighted that he’s committed his future to Gloucester.”