With the public release of iOS 8 landing today ahead of the new iPhone models shipping on September 19, developers are warning users not to upgrade to Apple’s new iCloud Drive feature just yet. The feature, which allows users to store and access files stored in iCloud on Mac, Windows, and iCloud-enabled iOS apps, is available to users on iOS 8 starting today, but won’t be available for Macs until Yosemite is released later this year. That means that upgrading today will cause syncing issues for apps that previously used other methods of syncing between Macs and iOS devices. The graphics above come from developers of iOS app DayOne, while developer Ginger Labs explained the problem in release notes for its popular iOS Notability app today:

Heads up! iOS 8 is coming soon. It includes a new syncing technology called iCloud Drive which is not compatible with iOS 7 or OS X 10.9 Mavericks. If you use Notability on Mac, we suggest not upgrading to iCloud Drive until Mac OS X 10.10 Yosemite is released later this year. After OS X 10.10 Yosemite is released, you can upgrade to iCloud Drive through Yosemite or using the Settings app on iOS.

Realmac Software, makers of popular Clear productivity app, offered a similar warning: “As OS X Yosemite is still pre-release (and not yet available) upgrading to iCloud Drive will prevent you from syncing with Clear for Mac until both OS X Yosemite is released and you upgrade to OS X Yosemite… Developers cannot work around the choice made when upgrading to iOS 8, so please make sure you pay close attention to the iCloud Drive screen shown after you update to iOS 8.”

So, if you’re using an app that syncs documents between iOS and OS X, choosing “Not Now” when Apple prompts you to upgrade to iCloud Drive on iOS 8 would probably be a wise decision (pictured above). You’ll be able to upgrade to iCloud Drive at any point through Settings—> iCloud—> iCloud Drive.