Google unveiled its first screenless fitness tracker, the Fitbit Air, earlier this month, and now reports are coming in from people who pre-ordered it that deliveries are starting. The device’s release date is tomorrow, May 26, and pre-orders were supposed to only start arriving then.

However, some orders got to the customers sooner, and perhaps as a consequence of this being a day earlier than Google anticipated, people with Android phones are having pairing issues. The Fitbit Air needs version 5.0 of the new Google Health app, but this hasn’t reached every device yet.

Google has confirmed the app pairing issue, and the company is working on fixing it. What happens is that when you try to pair the wearable, you get a message that it requires an updated version of the Google Health app, but that may still not be available to you.

A Google product team rep responded on Reddit to one user who was encountering issues saying Google is doing its best to “accelerate the rollout of the updated app on Android” to accommodate early deliveries, and this will be “available shortly”. Interestingly, this is not a problem on iOS, where the update is already live.