Google’s newly revealed Pixel 4 was met with excitement for several reasons, including the introduction of facial-recognition security. Google boasted that this method was a quick and effective way to keep your phone safe, but in practice, there is a major issue with this supposedly secure system.

The problem was first noticed by technology reporter Chris Fox, who tweeted that the Pixel 4 he was using could unlock even if his eyes were closed. He wrote his findings up for the BBC and included the video below as proof of what he found.

Proof, for those asking #madebygoogle #pixel4 pic.twitter.com/mBDJphVpfBOctober 15, 2019

Apple’s equivalent technology on the iPhone X, iPhone XS, iPhone XR and iPhone 11 series, Face ID, requires users to have their eyes open to unlock the phone, and it’s fairly obvious why this is the case once you start to think it through.

It means that if the Pixel 4’s owner is asleep, unconscious or dead, someone can still pick up their phone and access the owner's information without their knowledge, or even access locked apps or pay for items since these can be approved with facial recognition too.

No method of security is foolproof, of course, but this particular issue seems like a major flaw.

MORE: The Pixel 4 Has a Secret Weapon (And It's Not Hardware or Software)

Google does mention on its face unlock support page for the Pixel 4 that the feature works with closed eyes, but even with this warning users are still at risk. Google has been working on an option to disable or enable facial unlocking with eyes closed, but apparently this will not be available when the Pixel 4 launches Oct. 24.

It’s not all bad news for Google. Our early impressions of the Pixel 4 and Pixel 4 XL are very positive. We love its 90Hz display and Motion Sense gesture controls, plus just like the previous Pixel phones, the Pixel 4’s photos look great, aided by a new telephoto sensor on the back.

We’ll be updating our reviews as we get to know the Pixel 4 better, and no doubt this snag in one of its big new features will enter into our consideration.