Radio superstar Howard Stern is suing his employer, Sirius XM, over unpaid bonuses, reports The Wall Street Journal.

According to papers filed in court, Stern’s production company is seeking stock awards the satellite radio company owes him based on subscriber targets in Stern’s contract. Stern has yet to receive those bonuses and Sirius is reportedly refusing to make the payments.

Stern’s agents sought those payments in 2010, but were turned away by Sirius, prompting the legal action.

Sirius XM said it was “surprised and disappointed” by the lawsuit, according to the piece. “We have met all of our obligations under the terms of our 2004 agreement with Howard, his agent and production company,” the company said.