Apple plans to increase shipments of its Apple Watch, signaling there’s a growing appetite for its smartwatch.
Apple will ship 4.5 million watches in the fourth quarter for a total of 15 million this year, tech news site DigiTimes reported on Friday, citing unidentified suppliers. Shipments will jump to 20 million in 2018, the suppliers said.
Apple Watch, introduced in 2015, can tell time, in addition to running both Apple-created and third-party apps—effectively turning the device into a quasi-iPhone on the wrist. Prices vary depending on the model and wristband style.
Since its release, Apple (AAPL) has said only that its Apple Watch is selling well. The company has declined to divulge actual sales totals because of it says the information is proprietary.
Get Data Sheet, Fortune’s technology newsletter
That has left industry watchers with the task of trying to guess how many watches Apple has actually sold. And without confirmation from the iPhone maker, it means any numbers from third-party sources must be taken with some skepticism.
But sales and shipment data isn’t the only thing Apple Watch speculation is focused on. Several recent reports suggest Apple is working on a new, third version of the Apple Watch that it may announce in September. The watch could come with a cellular connection, allowing it to run apps without a connection to an iPhone, as in necessary with existing watch models.