As the U.S. Supreme Court prepares to rule on copyright infringement allegations over an Andy Warhol silkscreen of Prince, the U.S. Copyright Office is backing the photographer who shot the original image (which could prove hugely influential when the case goes before the Supreme Court in October). Photographer Lynn Goldsmith and the Andy Warhol Foundation have been in and out of court since 2017, after the photographer first saw the illustrations following the pop star’s death. The case is now set to go before the Supreme Court in October. However, this week the Copyright Office and solicitor general have urged the courts to rule that the photographer can pursue copyright infringement over the paintings.

[Read: Photographer Lynn Goldsmith Wins Appeal Over Warhol Art Copyright Case]

A brief from the copyright office and Solicitor General says that Warhol’s image of Goldsmith’s doesn’t fall under fair use. The brief says that treating the Warhol image under fair use because the colored image contains a different meaning “would dramatically expand the scope of fair use.” The brief also argues that Warhol’s licensing of the image to a magazine would affect the ability of the original artist to license her photograph, though noted that a museum display of the same image wasn’t likely to do the same.

Since the original lawsuit, the courts have gone back and forth over whether or not the silkscreen image constituted fair use. In the original case, a Manhattan judge sided with Warhol, calling the work transformative because it made Prince appear as an “iconic, larger than life figure.” A court of appeals, however, sided with Goldsmith, arguing that a transformative work should have a “fundamentally different” purpose. Bloomberg Law notes that the Supreme Court Case will likely help future court decisions “refine how they evaluate fair use and the line between transformative and derivative.”

Warhol, who died in 1987, is arguably the most well-known transformative artist. His work often creates social commentary over re-presentations of popular images, like his painting of a Campbell’s soup can and a series of Marilyn Monroe silkscreens similar to the Prince images. The nature of his work landed the artist in legal trouble with at least three court cases before his death. His works, however, are well known. The 2nd District Court of Appeals, in siding with Goldberg, warned against creating “a celebrity plagiarist privilege; the more established the artist and the more distinct that artist’s style, the greater leeway that artist would have to pilfer the creative labors of others.”

In submitting the brief, the U.S. Copyright Office and Solicitor General have asked to be part of an argument for the case on October 12.