Johnny Rockets restaurants could soon be getting a makeover following an offer from Fat Brands, Inc. to acquire the chain and add it to its portfolio.

Fat Brands, which already owns the Fatburger chain, announced it plans to buy the 1950s diner-style restaurant, known for its retro décor, burgers and shakes, for approximately $25 million. The deal is expected to go through by September, and will give them more than 700 franchised and company-owned restaurants after it is done, CNBC reports.

Chief Executive Officer Andy Wiederhorn did not say if part of the acquisition would involve changing some locations into Fatburger restaurants, but whether the chain changes to Fatburger or remains as Johnny Rockets, with ownership, it gives Fat Brands a chance to greatly expand its profile. Internationally, they currently have locations in Canada, China, Egypt, India, Iraq, Japan, Kuwait, Malaysia, Philippines, Qatar, Saudi Arabia, Singapore, Tunisia and the United Kingdom. The acquisition would expand that portfolio to Australia, Bahrain, Bangladesh, Bolivia, Brazil, Chile, Costa Rica, Ecuador, Honduras, Indonesia, Italy, Mexico, Nigeria, North Cyprus, Norway, Panama, Peru, Poland, South Korea, Spain, United Arab Emirates and Uruguay.

It will also greatly expand their portfolio in the United States as well, giving Fatburger ownership on locations along the East Coast, which they had previously left untapped, including in Connecticut, Florida, Georgia, Massachusetts, Maine, New York, Rhode Island and the Carolinas.

One thing Wiederhorn did say is planned is a modernization of the Johnny Rockets menu. The chain does include a Garden Black Bean Burger, as well as three salads, but mainly sticks to burgers, fries, shakes and other comfort food classics. By comparison, those seeking somewhat healthier options at Fatburger can choose from a Turkeyburger, Impossible Burger, Veggie Burger, bun-less Skinnyburger, Sweet Potato Fries and Strawberry and Vanilla vegan milkshakes.

Johnny Rockets
Johnny Rockets is set to be acquired by Fat Brands, Inc. The Johnny Rockets restaurant at the Universal Studios Hollywood CityWalk in Universal City, California is pictured on Feb. 9, 2017. George Rose/Getty Images