BlackBerry has filed a lawsuit against one of its own executives over his decision to leave the company for a position at Apple, as noted by iMore. Sebastien Marineau-Mes is BlackBerry’s Senior Vice President of Software until Apple offered him a role as Vice President of Core OS last December. That’s when Marineau-Mes told BlackBerry he’d be quitting in two months for Cupertino.

But because Marineau-Mes had signed a contract that required him to give six months notice before leaving (rather than two), the company filed a lawsuit to keep him around for four extra months. The court ruled that Marineau-Mes would have to stay on with BlackBerry for the full six months before he would be allowed to vacate his post.

BlackBerry called the lawsuit “unfortunate” but said that it expected Marineau-Mes to fulfill the contractual terms he agreed to when he accepted his job.