Apple is planning to increase security of its iCloud service by adding alerts, company CEO Tim Cook told The Wall Street Journal on Thursday.

Cook said email alerts and push notifications would be sent out whenever an account password is changed, iCloud data is restored to a new device or when a new device is used to access the account for the first time. That’s in addition to the two-step authentication procedure that users already have the option of activating, which Apple plans to expand.

The increased security measures come after hackers were able to access celebrity iCloud accounts and steal private photos, including nudes, which were then circulated online.

Cook admitted that Apple could have done more to encourage people to use stronger passwords and warn users of the risks posed by hackers.

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

He said the changes would take effect within two weeks.

Cook also defended iCloud security, telling the newspaper that hackers didn’t obtain passwords from Apple servers. Instead, they used a combination of phishing and correctly answering verification questions used to obtain and reset passwords.

Earlier this week, Apple reportedly fixed the “iBrute” bug, which critics say left iCloud exposed to a brute-force attack.