Boston Celtics guard Marcus Smart dribbles the ball upcourt during a game against the Philadelphia 76ers in January. Chris Szagola/Associated Press

The Boston Celtics have locked in their emotional leader for the long-term — and he’ll continue to play in the green and white for the next half-decade if all goes according to plan.

Marcus Smart and Boston have agreed to a four-year, $77.1 million max contract extension, which was first reported Monday by The Athletic’s Shams Charania.

The agreement keeps Smart in Boston through the 2025-26 season. Before the deal, Smart was heading into the final season of his four-year contract extension. Whether or not he would sign was one of the major storylines of the offseason, and the Celtics’ brass decided to lock him in.

While there were some murmurs that Smart could have been included in trade talks, the team elected to keep the 27-year-old guard, who’s also the longest-tenured Celtic.

Smart confirmed the news on social media, tweeting out some shamrocks to signify the extension. He also posted a video on Instagram with the caption “Let’s go 4 more…”

Smart averaged a career-best 13.1 points and 5.7 assists per game last season. The former all-defensive team player also has a significant impact on the locker room. Charania reported that Smart’s extension also includes a trade kicker.

First-year Boston coach Ime Udoka included Smart as one of the “pillars” of the team as it aims for another championship banner. Smart now gets to be in Boston long-term as the Celtics build around their All-Stars Jayson Tatum and Jaylen Brown.