AUSTIN (KXAN) — The Matt’s El Rancho Tex-Mex restaurant, which is known widely in the Austin area, is suing a Fort Worth café over their naming of a queso appetizer which Matt’s says is too similar.

Matt’s El Rancho, Inc. filed a complaint on Friday against the Horseshoe Hill Cowboy Café in Forth Worth — in addition to its owner/founder, Grady Spears, and his LLC Grady Spears BR — alleging that the Fort Worth restaurant is infringing the name of its well-known “Bob Armstrong Dip.”

According to the lawsuit, Matt’s is suing for trademark infringement, trademark dilution and unjust enrichment.

The lawsuit states that on several instances, lawyers for Matt’s sent the Fort Worth restaurant cease-and-desist letters and informal and formal verbal warnings. Matt’s says none of its final warnings and requests to stop selling the dip under the Bob Armstrong name were answered by Spears.

Matt’s says its “Bob Armstrong Dip” is well-known and has become so signature to its brand that it owns a strong common law right to the name. The Tex-Mex restaurant says the dip was created for famous Texas politician Robert Landis Armstrong during one of his regular visits in the early 1970s.

According to Matt’s, Armstrong had asked the chef to make an appetizer that was not on the menu, and what resulted was the dip.

Matt’s says the dip was an immediate hit and has been a part of its permanent menu since then. According to the restaurant, the dip has been widely publicized and has been included in books, news articles and television segments.

The lawsuit states that Matt’s owns a registration with the U.S. Patent and Trademark Office, which covers “Dips; cheese in the form of dips; snack dips, namely, cheese dips and queso dips.”

Matt’s and its representatives say they believe Horseshoe began using the name sometime before February 2018. The lawsuit says Matt’s believes that Spears and his restaurant began using the name knowingly to target similar customers and advertising.

Matt’s El Rancho is suing for trademark infringement, unfair competition, trademark dilution and unjust enrichment. In addition to unauthorized use of the “Bob Armstrong Dip” name, Matt’s says that Horseshoe’s use not only could damage its own dip due to lack of control on their part, but it also allowed the Fort Worth restaurant to profit off its work.

KXAN reached out to both Matt’s El Rancho and Horseshoe Hill Cowboy Café, but haven’t heard back from either at last report.