If iPhone X users are worried about a potential thief or attacker abusing the device’s new Face ID security system, they need only remember to give it a squeeze.

This information came by way of Apple’s senior vice president of software engineering, Craig Federighi, who responded to a concerned user’s email about the Face ID system. Keith Krimbel originally email Federighi with a few questions about the feature’s performance, and then tweeted the response he received.

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Specifically, Krimbel asked: “What will prevent a thief from taking my phone, pointing it at my face, and running?”

Federighi responded by explaining two key ways that users can mitigate that threat. The first, which seems a little obvious, is to not stare at the phone. While that may seem like common sense, it is important to remember that Apple noted the feature needs “your attention” to work, meaning a user’s eyes must be on the device.

However, the second method must be done before they relinquish the phone: Squeeze it.

“If you grip the buttons on both sides of the phone when you hand it over, it will temporarily disable Face ID,” Federighi wrote.

Federighi also wrote in the email that the Face ID would work with some sunglasses, but not all. The glass must let in enough infrared light in order to properly read the face.

While Apple said that Face ID is much more secure than its Touch ID fingerprint scanner, there have been some controversies surrounding the feature. The combination of using a swiping motion with the facial scanning has led some to predict that the feature will be difficult to use. Also, as ZDNet reported, different threat models could impact the effectiveness of the feature.

The 3 big takeaways for TechRepublic readers

  1. Apple iPhone X users can disable the Face ID system by squeezing the buttons on both sides of the phone, according to senior vice president of software engineering, Craig Federighi.
  2. The feature will also not work if the user doesn’t directly stare at the phone, and it may not work with some sunglasses.
  3. Face ID is a controversial feature, with some predicting it will be difficult to use and others claiming it might not improve security in some instances.