The upcoming Ghostbusters reboot has been shooting in Boston over the past two months, and The Boston Herald reports that Ozzy Osbourne may be making a guest appearance in the film. They say that he’ll be performing in the film during a heavy metal concert scene that was shot at the City Wang Theatre. Apparently, the Prince Of Darkness was spotted outside talking to a couple of crew members, and posters were seen in the area advertising a “Rock Revenge Fest featuring Ozzy Osbourne” as part of a “12 Hour Marathon of Metal.”

The Ghostbusters movie is scheduled to be released in the U.S. on 7/15/16.