Groupon has filed a suit against IBM in federal court for patent infringement.

The suit alleges IBM's WebSphere Commerce platform infringes on a 2010 patent that Groupon holds, making the daily deals site entitled to royalties based on the "billions of dollars" in revenue the platform has helped generate, Reuters reports. The platform allows merchants to send messages to customers with GPS-enabled devices based on their locations.

"IBM, a relic of once-great 20th Century technology firms, has now resorted to usurping the intellectual property of companies born this millennium," Groupon said in its lawsuit.

The suit, filed Monday in the U.S. District Court in Chicago, comes just two months after IBM filed its own complaint against Groupon for patent infringement. The tech giant accused Groupon of building its business model on IBM's intellectual property.