Apple made a simple change in iOS 9 that will make your iPhone a lot safer

Apple is rolling out its new iOS 9 Wednesday and with that comes a big security upgrade.

The new operating system will now automatically default to a six digit PIN to unlock your device, instead of just a four digit PIN. While this might seem like a small change, it actually makes breaking into your iPhone a lot more difficult.

With a four digit PIN, there are a possible 10,000 combinations. But with a six digit code, there are 1 million possible combos, making it a lot tougher for someone to crack your security code.

If you are currently using a four digit PIN and update your software, you will need to manually opt in for the six digit PIN.

You can do this in your settings under "Passcode." But if you are just enabling the feature it will automatically prompt you to use six numbers for your PIN.

While the six number passcode is not mandatory, it is highly recommended. If you would rather take your chances, though, and go with a four digit code, you can make that selection in your settings as well.

The tech giant is also rolling out built-in two-factor authentication as part of iOS 9. Once you enroll for the security feature, you will be prompted to enter a verification code each time you log into a new device or browser. The code will appear on your other Apple device or your phone.