Justin Bieber’s apology tour has hit another speed bump.

After canceling meet-and-greets and speaking out against award shows, the Purpose singer is now being sued by an independent artist who claims “Sorry” uses an unauthorized element of one of her songs.

Massachusetts songwriter Casey Dienel, who performs as White Hinterland, has brought a lawsuit against Bieber for allegedly borrowing a vocal riff from her 2014 track “Ring the Bell.” White Hinterland’s song begins with a loop of four notes that sounds very similar to the loop that features prominently throughout “Sorry,” though it doesn’t sound like Bieber’s single samples her recording of “Ring the Bell” directly. Dienel reportedly asked Bieber to stop using the song last December, a request which he ignored.

Dienel is also suing producers Skrillex and Blood, as well as the song’s co-writers Justin Tranter and Julia Michaels. In a 2015 interview with The Fader, Blood (aka Michael Tucker) spoke about writing the offending loop: "From the perspective of the producer, I find the muffled vocal chops to represent the people or situations in which Justin or the listener could be apologetic towards. The vocal manipulations make an ambiguous sound and a moment later Justin replies, 'Sorry.' I love that narrative."

Maybe “Sorry” isn’t about Selena Gomez at all. Maybe it’s actually about stealing a riff and then apologizing for the theft in the very same song that makes use of it.