Encrypted communication app Signal brought video calling to both its Android and iOS users in a new update on Tuesday, February 14. But with the refreshed app also comes support for CallKit on iOS, which introduces an apparent privacy issue into an app otherwise considered secure, The Verge reports.

CallKit, a new iOS 10 feature, makes Signal act more like the regular phone app. It allows Signal calls to be answered from the lock screen and lists those calls in a user’s “Recent Calls” list. But while it might be more convenient, Signal notes that if users decide to opt in to CallKit, some of their data might sync to iCloud, including who they called and how long they talked. That probably won’t sit well with privacy-minded people, so for now, CallKit is optional and if turned on, will only work when both parties opt in so as to avoid data leakage. Video calling is also optional.

Signal says that it’s still assessing CallKit. In the future it might only display “Signal users” in an iPhone’s call log, or it might offer a privacy tutorial to help users understand their settings options.