(Screenshot via YouTube.)

Ellen DeGeneres celebrates the 20th anniversary of coming out in a special commemorative episode of her talk show on Friday.

DeGeneres’ character Ellen Morgan came out on the sitcom “Ellen” in an episode titled, “The Puppy Episode.” It aired on April 30, 1997 and was the first time a lead TV character had come out as gay. DeGeneres came out at the same time in real life on the cover of Time magazine with the headline, “Yep, I’m Gay.”

In a preview clip, DeGeneres explains why the now iconic sitcom episode was titled “The Puppy Episode.”

“It was called ‘The Puppy Episode’ because we wanted to keep it a secret until it aired and because ‘Ellen Throws Her Career Away’ seemed too on the nose,” DeGeneres joked to the audience. “Actually, the real reason we called it ‘The Puppy Episode’ is cause when the writers told the executives that they wanted me to come out because my character needed to be in a relationship after four years of not being in a relationship, someone at the studio said, ‘Well, get her a puppy. She’s not gonna come out.’ And so, we called it ‘The Puppy Episode.'”

DeGeneres is joined by guests Oprah Winfrey and Laura Dern who both played important parts in the comedian’s coming out. Dern played Susan in the episode, a woman who helps Ellen come to terms with her sexuality. Winfrey played Ellen’s therapist and in real life had DeGeneres on as a guest for an hour-long episode of “The Oprah Winfrey Show.”

“You wouldn’t have been able to open hearts and touch hearts and change people’s minds and make a difference in the world had you not had the courage to do that,” Winfrey tells DeGeneres in the clip.

In a sneak peek of the episode posted on Instagram, DeGeneres gets emotional recounting the big moment.

I can’t wait for you to see this on tomorrow. It might be my favorite episode ever. What a difference 20 years makes.

A post shared by Ellen (@theellenshow) on Apr 27, 2017 at 5:01pm PDT

“It was the hardest thing that I ever had to do in my life and I would not change one moment of it because it led me to be exactly where I am today standing in front of all of you,” DeGeneres says in her monologue.

Other special guests include her “Ellen” co-stars Joely Fisher and David Anthony Higgins and DeGeneres’ wife Portia de Rossi.

“The Ellen DeGeneres” commemorative episode airs Friday at 3 p.m.