Wholesale mega-chain Costco is eyeing an expansion to their hot food menu (at least in Southern California), tinkering with a new burger that looks an awful lot like the one Shake Shack basically perfected years ago.

The burger was first uncovered by the Orange County-based Foodbeast team, who tracked it down near Long Beach. According to conversations they’ve had with Costco corporate, the burger is in a localized testing phase at the moment, which means it’s only available at Costco locations in Pacoima, Lakewood, and Corona, plus some outlets up in the Seattle area. Here’s the Foodbeast description, as lifted from the Costco team:

It's an organic beef patty, topped with romaine lettuce, smoked Thousand Island dressing, tomatoes, and cheddar cheese, all placed between fluffy, sweet Chicago-style buns.

Foodbeast has since clarified that their “Chicago-style” bun is actually just a lighter version of challah, but in testing out the Pacoima location it’s definitely got the same sponginess and slight sweetness as the Martin’s potato rolls that Shake Shack uses.

The two opposing burgers actually look remarkably similar in their ultimate assemblage — though Costco puts their lettuce and tomato on the bottom, not the top, like how Shake Shack does their Chick’n Shack sandwiches. There’s also none of the signature sear found on the Shake Shack iteration, but what’s lost in skill is made up for in the patty’s heft, apparently.

For a visual example, check out the Costco burger shot above, and then the Shake Shack version below.

For now Costco’s burger will reportedly remain only in select markets, but Foodbeast says a larger roll-out is planned starting in March of next year. The current price is also $4.99, meaning a (real) single Shack burger is only .30 cents more. If interested in trying one of Costco’s attempts, get over to Lakewood, Pacoima, or Corona sometime soon.