Several months after losing a motion for summary judgment, Encyclopaedia Britannica is facing another possible setback in its legal malpractice lawsuit against Dickstein Shapiro.

In a Feb. 20 order, U.S. District Judge John Bates asked Britannica to explain why he should still be able to hear the case, in light of a ruling the same day from the U.S. Supreme Court that narrowed the ability of plaintiffs to pursue legal malpractice claims involving patent matters in federal court.

The high court found in Gunn v. Minton that state legal malpractice claims over how lawyers managed patent matters couldn’t be brought under federal patent law. The justices reasoned that regardless of how a legal malpractice claim resolved, it wouldn’t affect the original federal patent litigation.

The decision isn’t a death knell for Britannica. Bates could still have jurisdiction over the case through diversity, meaning the dispute is over more than $75,000 and is between parties in different states. The judge wrote that Britannica failed to establish complete diversity because they didn’t identify the location of the Dickstein partners named in its lawsuit.

Britannica is located in Chicago and was incorporated under Delaware laws, while Dickstein is based Washington. Bates gave Dickstein until Feb. 28 to tell Britannica if it has any partners located in Illinois or Delaware, and he gave Britannica until March 7 to make its case for why Bates shouldn’t dismiss the lawsuit from Washington federal court for lack of jurisdiction.

A lead attorney for Britannica, Robert Cummins of The Cummins Law Firm in Chicago, did not immediately return a request for comment. Lead counsel for Dickstein, Goodwin Procter counsel John Aldock, also could not be reached.

Britannica originally sued Dickstein in 2010, accusing the firm of negligently handling patent prosecutions. Dickstein denied any wrongdoing.