Apple has issued an urgent warning to iPhone users about a crucial iOS update that is the only way to protect iPhones from “the extremely malicious Pegasus software.”

According to Apple, Pegasus can completely take over an iPhone and only 86 percent of iPhone users have updated their phones by installing the iOS version 9.3.5.

Apple is urging all users to update their phones to eliminate the vulnerability. Employers who allow employees to use their iPhones for work purposes may wish to encourage their employees to update their iPhones to protect company data from Pegasus.

I updated my phone when the alert on my phone requested the update. Instead of clicking “later,” update your phone now. It only takes a few minutes and is “crucial” according to Apple.