For those of you who are on a limited mobile data plan and are using an iPhone running on iOS 9, here’s one very important feature you need to turn off – Wi-Fi assist.

Wi-Fi Assist is a new feature in iOS 9 that helps you maintain a stable internet connection by switching to mobile data when your Wi-Fi connection is weak. Sadly though, while it sounds like a very convenient feature to have turned on, some users are reporting that their iPhone is using way more data than before. If you have plenty of mobile data to spare, it’s ok, but if you’re on a limited plan, tap the Settings app and turn it off.

To turn Wi-Fi Assist off, simply open the Settings app, open up Cellular settings, and scroll to the bottom until you see Wi-Fi Assist, and toggle it off. This feature is turned on by default so for those who plan to get an iPhone 6s or iPhone 6s Plus when it arrives Malaysia next month, you know what to do.

(Source: Engadget)