The estate of Jack Kirby has filled an appeal against the decision of a U.S. District Court judge in favor of Marvel, reports Deadline.com. The judge granted Marvel summary judgment in the case, which hoped to regain certain rights to characters Kirby created for the company. The court ruled that Kirby was a freelance writer and that he did not retain the copyrights to his creations.

The lawsuit stems from the Kirby estate issuing termination letters on copyrights held by Marvel and Disney.

The Kirby estate is represented by Marc Toberoff, the lawyer who won back rights to Superman for the estates of the character's creators.