We’ve all been there: you hurry to download the latest iOS update, excited about new features on your old phone, only to find that your phone is running slower than ever after it finishes downloading.

People have speculated that this may be done on purpose, a sinister plot by Apple to include hidden software with every update, gradually making older phones unusable so that the owner is forced into an upgrade before they are ready.

The truth, it now seems, is much less nefarious.

Turns out that the problem may not be with the software, but with the phone itself, or more specifically the built-in battery. New evidence has found that as an iPhone battery ages and loses capacity, the same as any other battery will, the phone begins to reduce the chipset’s clock speed in order to boost the life of the battery.

The problem seems to have started around the time of the iOS 10.2.1 update when people began to see notifications popping up that their battery needed to be serviced. This was the update that people also started to experience the 30 percent bug, where their phones would spontaneously drop from 30 percent battery to 0 and shut off without warning.

Fortunately fixing the problem can be very simple, replace the old battery and your iPhone can be running as good as it ever did, without being forced into an upgrade that you don’t want.

Apple hasn’t made it easy for the average person to swap out the battery in their phones like some of their competitors have, but a qualified repair shop will be able to get your battery changed out for a new one and have your phone up and running again in no time.

This is great news for anyone looking to extend the life of their iPhone, but has been desperate for a solution as it becomes harder and harder to use. Instead of running out to the closest phone store and spending money on the latest model, an iPhone repair done by a knowledgeable professional might be the solution that can save you time, money, and hassle.