Windows 10 Mobile's rollout to last-gen Lumia devices has hit a few snags, but there are signs that Microsoft is on the verge of flicking the switch.
A Neowin reader has spotted a beta app called Mobile Upgrade Advisor hidden away on the Windows Phone store.
It's a tool that tells Windows Phone users whether their device is eligible for Windows 10 and helps them free up space for the OS.
Although the app isn't available for the public to download, its very existence suggests that Microsoft is almost ready to dish out the update.
There is still no official word about which phones will receive Windows 10 Mobile, but those with less than 8GB of storage will not be supported.
That rules out the likes of the Lumia 530, but a variety of Nokia-branded handsets are expected to be eligible.
Microsoft ushered in Windows 10 Mobile with the launch of its latest flagship smartphones - the Lumia 950 and the Lumia 950 XL - last month.