Walt Disney Animation Studios is replacing Jennifer Lee, its chief creative officer, after an uneven six-year tenure.

Director-writer Jared Bush is replacing Jennifer Lee as chief creative officer of the Walt Disney Animation Studios as Lee returns to filmmaking full time at the company and stewards the Frozen franchise, Disney announced Thursday. He’ll report to Disney Entertainment co-chairman Alan Bergman, effective immediately.

Lee is writing and directing “Frozen 3” and writing “Frozen 4” with Marc Smith — the sequels to Disney Animation’s 2013 “Snow Queen”-inspired cultural hit “Frozen,” for which she served as writer/director. The movie made $1.3 billion worldwide and earned two Oscars, for best animated feature and for earworm song “Let It Go.”