Apple has added extra security measures to iCloud, including alerts if someone tries to change your account password, download iCloud files to a new device, or a log a new device onto an account. Users can then change their passwords immediately or notify Apple security. The alerts will start in two weeks, CEO Tim Cook told the Wall Street Journal.

In addition, Apple will also increase its use of two-factor authentication, expanding it to cover access to iCloud accounts from a mobile device when it releases its iOS update later this month.

The changes come in the wake of the recent leak of a large number of photos from celebrity accounts, allegedly from hacked iCloud accounts. Apple previously released a statement denying any breach within its systems, but admitting that celebrity accounts were compromised by attackers using standard phishing techniques.

In his interview with the WSJ, Cook reiterated that point and said that Apple could have done more to make people aware of hackers potentially targeting their accounts or how to create more secure passwords.

“When I step back from this terrible scenario that happened and say what more could we have done, I think about the awareness piece. I think we have a responsibility to ratchet that up. That’s not really an engineering thing,” he said.

Apple also said it will take more steps to make people aware of two-factor authentication, since most users currently don’t use it. Apple told WSJ that if the celebrities whose accounts here hacked had used two-factor authentication, then hackers would not have been able to guess the currect answers to their security questions.