IBM is suing Groupon over alleged patent infringement, reported Chicgo Tribune. It's the latest in a series of lawsuits the computing pioneer has filed against tech companies.

IBM filed a lawsuit in Delaware district court alleging that the Chicago-based online marketplace ignored repeated alerts stemming to 2011 that it was unfairly using IBM inventions. It filed a similar suit against Priceline in February 2015, accusing the online travel booking company of infringing on four of its patents. 

Twitter reportedly paid $36 million to avoid a patent infringement lawsuit IBM threatened just before the company's IPO in 2013. IBM also reached a settlement with Amazon in 2007 over a similar suit. IBM claims Groupon infringed on four patents, two from the late 1990s, one from 2006 and another from 2009.

"Groupon has refused to engage in any meaningful discussions about reaching a license agreement to end its infringement of IBM’s patents,” the complaint reads. "Instead, Groupon has continued to willfully infringe IBM’s patents so as to obtain the significant benefits of IBM’s innovations without paying any compensation to IBM."