Credit: Getty Images; ABC

A historic executive shake-up at ABC: Entertainment chief Paul Lee has stepped down from his post after six years leading the network’s programming department.

Lee has been replaced by ABC’s vice president of drama development, Channing Dungey, who is the first African-American to ever lead the entertainment division of a major broadcast network.

Dungey helped develop ABC hits such as Scandal, How to Get Away With Murder, Quantico, and Once Upon A Time. The announcement was made by Disney Media Networks co-chairman Ben Sherwood.

“I’m thrilled and humbled that Ben has entrusted me with this tremendous opportunity,” said Dungey, who is also the sister of Once Upon a Time and Brooklyn Nine-Nine actress Merrin Dungey. “And I am truly grateful to Paul for being a valued mentor and friend. I’ve had the great honor of working alongside the talented team at ABC for many years and look forward to starting this exciting new chapter with them.”

A change in the network’s leadership has been expected for awhile: ABC is currently in last place in the ratings among the Top 4 broadcast networks. Season-to-date, ABC is averaging 6.6 million viewers in primetime and a 1.8 rating among adults 18–49, down 14 percent from this time last year (including DVR). By comparison, CBS — which just aired the Super Bowl — is in first place with a 2.5 demo rating, NBC is right behind with a 2.4, and Fox has a 2.1 (the fifth broadcaster, The CW, has a 0.7).

Lee said in a statement: “Leading ABC has been a fantastic experience. I’m especially proud of the incredible team I built and the strategic, creative vision we established and successfully executed for both the network and studio. Together, we’ve transformed ABC into one of the strongest brands in television.”

Lee then listed 10 ABC or ABC Studios shows as examples of his track record, including Scandal, Black-ish, Once Upon, and The Goldbergs.

Sherwood, who according to The New York Times pushed for the executive change in response to the network’s sagging ratings and Lee’s programming decisions, made this statement: “Channing is a gifted leader and a proven magnet for top creative talent, with an impressive record of developing compelling, breakthrough programming that resonates with viewers. We thank Paul for his many accomplishments at ABC and his devotion to the ABC brand, and we wish him continued success in the future.”

The executive change could impact the fate of certain bubble shows since new top programming executives tend to be less inclined to renew struggling titles that were greenlit by their predecessor. So shows like Agent Carter, Castle, The Muppets, and Fresh Off the Boat could face stronger renewal scrutiny in May. At least one ABC show’s executive producer, The Muppets‘ Bill Prady, seemed to react to the news on Twitter: