The bottle looks cool, the name is pithy, and it’s made right here in DC: Since its debut this past fall, Green Hat gin has become one of the hippest sips in Washington.

Michael Lowe and his son-in-law, John Uselton, opened New Columbia Distillers—the District’s first microdistillery—in October in the Ivy City neighborhood of Northeast. It’s the first time in more than a century that anyone has distilled spirts within city limits, as Washingtonian reported in a feature about the duo last fall. But now Lowe and Uselton are dealing with one of the worst nightmares of any new business-owner: a legal dispute over their brand.

Green Farms II, a company based in Brooklyn, filed a lawsuit against New Columbia Distillers in federal court in New Jersey in November claiming that the sale of Green Hat gin will likely cause confusion with Green Farms’ gin products, sold under the brand Greenhook Ginsmiths.

As first noted by the National Law Journal, New Columbia Distillers this week filed its own action in DC federal court. In an effort to put to rest the assertions made by Green Farms, New Columbia Distillers is asking the DC court to declare that its trademark for the Green Hat name does not infringe on the Greenhook Ginsmiths trademark. New Columbia Distillers is not asking for damages, or for Green Farms to change its name. It just wants the court to determine that no one’s trademark is being violated.

The Green Hat name is a reference to bootlegger George Cassiday who, during Prohibition, sold booze to members of Congress while wearing his signature green hat. In a letter to Green Farms’ attorney, one of New Columbia Distillers’ lawyers points out a number of other trademarks for names connected to alcoholic drinks that include the word “green,” such as Green Devil, Green Beast, and Green Spot.

“I haven’t tried it, but I’m sure that Greenhook Ginsmiths makes a very nice gin. I can tell you from experience that Green Hat’s gin is delicious,” said Venable partner Damon Wright, the lead attorney representing New Columbia Distillers, in a statement. “Green Hat hopes the lawsuit can be quickly resolved, so the two companies can simply compete in the marketplace.”

Green Farms’ attorney, Jon Fallon, has not yet returned a request for comment. We will update if we hear from him.