Erik Per Sullivan, who played Dewey on 'Malcolm in the Middle,' will not be returning for the revival series. Bryan Cranston says he is going to Harvard.

A reason has been given for why original Malcolm in the Middle star Erik Per Sullivan turned down the upcoming Disney+ revival. The former child actor portrayed Dewey, the second youngest son. The role will instead be played by Caleb Ellsworth-Clark in the four-episode revival.

Erik Per Sullivan, who starred as Dewey in the early-2000s fox sitcom, is the lone original-series star that will not return to the Disney+ revival. On Wednesday, Bryan Cranston, who played the hapless dad Hal on the sitcom, explained why.