Jayson Tatum‘s summer continues to get better. The Boston Celtics and the superstar forward are finalizing a five-year, $314 million supermax contract extension through the 2029-30 season, according to The Athletic. The deal would be the largest in NBA history. The Celtics intend to reward Tatum after he helped the franchise achieve its 18th championship following the defeat of the Dallas Mavericks in five games in the NBA Finals last month. During that series, Tatum averaged 22.2 points, 7.8 rebounds and 7.2 assists. The deal locks down Boston’s superstar duo — NBA Finals MVP Jaylen Brown and Tatum — for the future. Brown’s five-year, $285 million dollar contract kicks in at the start of the 2024-25 NBA season. The news of Tatum’s deal comes hours after the Celtics also agreed to sign Derrick White to a four-year, $125.9 million contract extension, according to reports. White’s deal includes a player option. The Celtics selected Tatum with the third overall pick out of Duke in the 2017 NBA Draft. The former Blue Devil is a five-time All-Star and four-time All-NBA Team Selection. The 26-year-old has been a First-Team All NBA selection in the past three seasons. Tatum — along with Celtics teammate Jrue Holiday — is set to represent Team USA in the Paris Olympic Games this summer.