Some iPhone X users have complained on Twitter about Face ID failing to recognise them in the morning. The feature is supposed to account for small facial changes like hair and makeup.

It also recognises faces through sunglasses and shaving foam. However, it struggles to recognise some users’ morning face. It’s possible the error, for some users, is due to facial swelling in the morning, something that isn’t unusual or serious.

Face ID does assign a higher value to some parts of the face. For instance, Face ID will still work if the mouth is covered but not the nose.

So for those of us who don’t wake up “flawless”, there’s always the passcode option to get into your phone.