The long-running rivalry between the country’s top premium credit cards is about to heat up again.

JPMorgan Chase announced last week that a refresh of its Sapphire Reserve — the travel and dining rewards card that went viral when it arrived in 2016 — was imminent.

In response, American Express on Monday said that “major” changes were coming to its consumer and business Platinum cards later this year. While short on details, the New York-based card company said that its update would be its largest ever investment in a card refresh.

“We are going to double down on the things we know based on the data that our card members love,” said Amex President of U.S. Consumer Services Howard Grosfield in an interview. “But more importantly, we’ll bring a whole bunch of new and exciting benefits and value that will far, far, far exceed the annual fee.”

American Express pioneered the premium credit card space decades ago with cards that bundled perks at airlines and hotels with access to its own network of high-end airport lounges. But JPMorgan shook up the industry in 2016, igniting stiff competition among card issuers with a lavish sign-on bonus and other incentives for its Sapphire card.

The expectation among industry experts is that both companies will offer ever-longer lists of perks in travel, dining and experiences, while potentially raising their annual fees, as has been the pattern with recent updates.

The Platinum card has a $695 annual fee, while the Sapphire has a $550 fee.

On Reddit and other forums, card users circulated rumors that JPMorgan was hiking the annual fee on its Sapphire product to $795. A JPMorgan spokesperson declined to comment.

The new Platinum card will launch in the fall, Grosfield said.