Sarah Michelle Gellar, the Buffy the Vampire Slayer star who got her start on All My Children, will make a farewell appearance on the cancelled soap.

Gellar, currently promoting her new series Ringer, confirmed her All My Children cameo on Thursday, during an interview with reporters attending the TV Critics Tour in Los Angeles.

After a 40-year run on ABC, All My Children will air its last episode on Sept. 23. It will then be resurrected as a web series.

Gellar will not portray Kendall Hart, the long-lost daughter of Susan Lucci's character and the role that earned her a Daytime Emmy Award at the age of 18.

"I don't want to be Kendall. That's Alicia's role," Gellar said, referring to All My Children regular Alicia Minshew. "I have no idea what I'm going to be doing."

Instead, she'll appear in a one-day guest spot as a different character.

"I just wanted to be part of it," she said.

Gellar is not the only alumnus returning in the soap's final weeks: Transformers actor Josh Duhamel is currently reprising his role as conman Leo du Pres.

Gellar returns to TV after an eight-year hiatus in Ringer, which debuts Sept. 13 on the CW network in the U.S. and on Global in Canada. She plays a woman who steps into her estranged twin sister's place when her life goes horribly wrong.

One Life to Live — another soap whose cancellation was announced this spring — will wrap up in January 2012, after 42 years on the air.

With files from The Associated Press