Black Sheep has waged a legal war against Universal Music Group.

The 1990s hip-hop duo, composed of Andres “Dres” Vargas Titus and William “Mista Lawnge” McLean, is spearheading a hefty class action lawsuit over unpaid royalties. According to Billboard, the plaintiffs claim UMG inked a “sweetheart” deal with Spotify in 2008, agreeing to accept lower royalty rates in exchange for cash and equity in the streaming service.