Have iOS9? Turn off this setting to avoid overage fees.

If you upgraded your iPhone to iOS 9, or if you bought a brand new iPhone 6s or 6s Plus recently, then you might want to turn off the Wifi Assist feature.

Wifi Assist is a setting that prompts your phone to switch to cellular data when your Wifi connection is poor. In theory, this could be a nifty feature that allows for more seamless loading.

Watch Out for Overage Fees

The problem is that Wifi Assist is on by default in iOS 9, and you don't easily know when it's switching to data. If you have a small monthly data allotment, then you could quickly eat through your plan without realizing it and end up paying overage fees.

While Apple has tried to clarify the details behind Wifi Assist, a couple this week filed a class action lawsuit for $5 million. These consumers are annoyed that Wifi Assist is on by default without proper warning from Apple that the feature could potentially result in data overages.

How to Turn Off Wifi Assist

As we mentioned though, this feature can easily be turned off. If you're worried that it might push you over your monthly data limit, then go into your settings and select "Cellular." Then, scroll all the way to the bottom of the screen and turn off Wifi Assist.

Readers, have any of you experienced overage fees due to Wifi Assist? What do you think about the lawsuit? 

This article first appeared in DealNews.