Block may have hit a snag in its rebranding effort. Per The Wall Street Journal, H&R Block is suing the company formerly known as Square. In a federal complaint filed on Thursday, the tax-prep firm said the name change could hurt its brand. It wants Jack Dorsey’s payments outfit to stop using the name and a logo it contends is “nearly identical” to its own.

“The goodwill that Block has so carefully created and nurtured over the past six decades is now under attack by a Silicon Valley fintech company,” it said. We’ve reached out to Block, the other one, for comment.

Square changed its name to Block at the start of December. At the time, the company said it wanted a name that better reflected the expansion of its business beyond payments and the growing importance of blockchain technologies to its identity. Since its founding in 2009, Block’s business has expanded to include stock and crypto trading, money lending and even music streaming.

Where things may get tricky in terms of a trademark infringement complaint is that Block bought Credit Karma’s tax-prep business in 2020. It plans to offer tax returns through its Cash App. In trademark cases, a court will look at similarities between the products and services two companies offer. It will also consider how the two may compete against one another in the future. Jack, if you’re reading this: it’s never been a better time to rebrand the company to “Tesseract.”