Katy Perry says she’s willing to squash her beef with Taylor Swift and even go as far as create music with her … on one condition: The 1989 singer has to apologize.

On Saturday evening, Perry went to Twitter to answer a slew of questions from her fans, one of whom wanted to know if she’d ever work with Swift after their highly publicized feud. The 31-year-old artist gave a brief and honest answer: “If she says she’s sorry, sure!”

Rumors of the singers’ beef have circulated for almost two years. In a 2014 interview with Rolling Stone, Swift said her 1989 track “Bad Blood” about another female artist, whom she declined to name.

“For years, I was never sure if we were friends or not," she says. "She would come up to me at awards shows and say something and walk away, and I would think, 'Are we friends, or did she just give me the harshest insult of my life?'" Then last year, the other star crossed a line. "She did something so horrible," Swift says. "I was like, 'Oh, we're just straight-up enemies.' And it wasn't even about a guy! It had to do with business. She basically tried to sabotage an entire arena tour. She tried to hire a bunch of people out from under me.”

People came to the conclusion that Perry was the unnamed female artist, as she reportedly took one of Swift’s backup dancers for her tour. A year later, the 26-year-old singer denied that “Bad Blood” was about Perry, and was, in fact, about an ex-boyfriend; however, many people weren’t convinced.

It’s no secret that Swift has had her fair share of celebrity feuds. Over the years, she has had beef with everyone from Nicki Minaj and Camilla Belle to Tina Fey and Amy Poehler. And who could forget her beef with Kanye West and Kim Kardashian? It’s clear Perry isn’t the only one who thinks Swift owes an apology.