Something to look forward to: 4K movies have been available on Google Play Movies for a couple of years now, but upgrading purchased HD titles to the higher resolution isn't possible. Thankfully, Google may soon be adding the option---and it could be free.

For the many people who have bought HD movies from Google's service, there's no way to upgrade the quality or delete the title from your account and re-purchase the 4K version. But Android Police found evidence inside version 4.8 of the Play Movies app that suggest this might be about to change.

The teardown reveals several lines of codes related to 4K upgrades. "[a number] of your movies just got a free upgrade to 4K," reads one line.

While extra text relating to upgrade pricing could be added at a later date, a company offering free 4K upgrades to owners of HD movies isn't without precedent. Last year, Apple revealed it would allow users to upgrade HD titles purchased from iTunes to 4K for free, though there are some limitations.

When it comes to SD movies, it's unlikely that any potential free upgrade offer will apply.

There are a number of 4K movies and shows available on Google Play, but the upgrade refers to those titles that have up to now only been available in HD.

We'll have to wait for the official word from Google to find out when or if it plans to roll out the free upgrades, and which movies it applies to.