Emma Watson and the youngest ever Nobel Prize laureate Malala Yousafzai have used their powerful voices to champion equality for women.

According to the Christian Science Monitor, the Harry Potter actress, 25 and Yousafzai sat down for an interview Tuesday at the premiere of the documentary, He Named Me Malala, which chronicles the 18-year-old Pakistani education activist’s fight for girls and stars Watson, who serves as the interviewer.

The 23-minute video was posted on Watson’s Facebook page and has now been viewed nearly 4 million times.

In the video, Emma Watson, a UN ambassador for women, and Yousafzai bonded over many topics, including their brothers, Hillary Clinton, their love for the book A Thousand Splendid Suns, and most importantly, the definition of feminism.

“This word ‘feminist’ has been a very tricky word,” said Malala, to which Watson gasped in delight.

When I heard it for the first time, Malala goes on, “I hesitated in saying ‘I’m a feminist.’”

Malala Yousafzai tells Emma Watson: "We should all be feminists" https://t.co/roV73FXo5z pic.twitter.com/71cw5xB1v6

— Huffington Post (@HuffingtonPost) November 6, 2015

“Then after hearing your speech, when you said, ‘if not now, when? if not me, who?’,” Malala says, referring to Watson’s landmark UN speech about men participating in feminism, “I decided there’s nothing wrong with calling yourself a feminist. I am a feminist, and we all should be feminists because feminism is another word for equality.”

Time magazine reports that Emma Watson said the most profound moment of their interview was when Yousafzai identified herself as a feminist, saying that she was surprised to hear the Yousafzai use the hot-button word.

Emma Watson and Malala Want to Make Feminist a Friendly Word https://t.co/2fWNOp1wTn pic.twitter.com/v3JFsdXhzo

— ELLE Magazine (US) (@ELLEmagazine) November 6, 2015

“I think this gesture is so emblematic of what Malala and I went on to discuss. I’ve spoken before on what a controversial word feminism is currently,” Emma Watson wrote on Facebook. “I want to make it a welcoming and inclusive movement. Let’s join our hands and move together so we can make real change. Malala and I are pretty serious about it but we need you.”