Scammers don’t need to physically steal your credit or debit card to rip you off. Small devices implanted in card readers, known as skimmers, can put your card information in the hands of nefarious actors without you even noticing. But while the devices can be hard to spot, there’s a new way to protect yourself against them. An app called Skimmer Scanner can help identify if there’s a skimmer nearby, as the credit card blog The Points Guy reports.

Credit card skimmers are especially prevalent at gas pumps, many of which haven’t been updated with more secure chip technology. Skimmer Scanner is designed to be used before you fuel up, allowing you to see if you’re going to be paying for more than just the price of gas.

Skimmer Scanner

You just open the app before you stick your card in, and hold your phone near the pump. Skimmer Scanner uses Bluetooth technology to detect whether a skimmer device is working within the pump’s card reader. If you get a positive hit, you should alert the attendant and local authorities, and fuel up elsewhere.

The app does come with some caveats, though. According to the developers, “Using this app may authenticate your Android device to illegally installed skimmers. Please check your local laws before installing this product.” And just because there’s no skimmer detected doesn’t mean you’re guaranteed to be safe using that machine. “There's always a risk to sticking your card in a strange machine,” they note.

The app is available for Android on Google Play. According to The Points Guy, the company is currently working on an iPhone version.

[h/t The Points Guy]