Apple is taking a swipe at Facebook and other messaging apps by making a small but significant change to its mobile operating system.

The change will restrict a feature that apps like Facebook Messenger and WhatsApp used to make voice calls over the internet. Right now, the calling feature in these apps runs in the background even when it’s not in use, ensuring the apps can connect calls faster but also making it possible for them to perform other, unrelated tasks such as collecting data. Now, Apple is restricting that background access so that it can only be used for internet calls.