The Google Pixel 4's Face Unlock has been updated.
Now the smartphone is able to "recognise" the owner's face "better over time" thanks to the latest improvement in the Pixel Features Drop.
Google states: "When it's on, face unlock images are occasionally used to create improved face models.
"This helps recognise you better over time."
The Face Unlock works even if a person has their eyes closed.
The tech giant confirmed ahead of the phone's release that the security system allows access to a person's device even in the event their eyes are shut.
In a statement, the company said: "Pixel 4 Face Unlock meets the security requirements as a strong biometric."
As a comparison, Apple's Face ID system makes sure the user is "alert" and facing the phone before it can be unlocked.
Before the model was launched, the Pixel product manager Sherry Lin insisted: "There are actually only two face [authorization] solutions that meet the bar for being super-secure. So, you know, for payments, that level - it's ours and Apple's."