One of the world’s top tech companies is suing Samsung for patent violations, only this time its not Apple.

Microsoft announced this afternoon that it filed a lawsuit against Samsung in the U.S. District Court of Southern District of New York, for not paying up on cross-licensed intellectual property from Microsoft that its been using in smartphones since 2011.

David Howard, Deputy General Counsel at Microsoft, says Samsung was happy to pay for the tech when the two companies entered into a contract in 2011 when it only shipped 82 million Android phones. Fast forward to 2013, and Samsung shipped 314 million Android, thus becoming the world’s top smartphone maker in terms of units sold, which is right when it decided it didn’t need to pay Microsoft anymore.

“In September 2013, after Microsoft announced it was acquiring the Nokia Devices and Services business, Samsung began using the acquisition as an excuse to breach its contract. Curiously, Samsung did not ask the court to decide whether the Nokia acquisition invalidated its contract with Microsoft, likely because it knew its position was meritless.”

Even Microsoft couldn’t have imagined how quickly Samsung’s smartphone business would take off (and then plummeted), but even though though the two have a long history of history of collaboration that Microsoft “values and respects,” they’d still like to get a piece of action. Maybe no one’s told Samsung’s three CEOs yet, but Redmond’s marketshare hasn’t been doing too great.