The highly successful sitcom Friends, which ran from 1994 to 2004, has received a lot of criticism over the years for focusing on six white, heterosexual individuals living in New York City—one of the most diverse cities in the world.

The show’s co-creator, Marta Kauffman, recently addressed the issue, which she said she found “difficult and frustrating” at first.

“I’ve learned a lot in the last 20 years. Admitting and accepting guilt is not easy. It’s painful looking at yourself in the mirror. I’m embarrassed that I didn’t know better 25 years ago,” Kauffman said in a Zoom interview with The Los Angeles Times.

In an attempt to apologize for the lack of diversity on the show, Kauffman pledged $4 million to the African and African American studies department at her alma mater, Brandeis University.

“It took me a long time to begin to understand how I internalized systemic racism. I’ve been working really hard to become an ally, an anti-racist. And this seemed to me to be a way that I could participate in the conversation from a white woman’s perspective,” she told Brandeis.