Fitbit is changing how it calculates sleep duration, but many users have complained of the tracking actually getting worse instead of better.

Fitbit has reworked its sleep tracking system, and it may result in your wearable reporting a worse's night's sleep as a result.

“Your sleep tracking just got more accurate,” according to Fitbit, this is the first in a “series of upcoming improvements” to sleep tracking.

As spotted by 9to5Google, Fitbit has published a new page detailing changes to its sleep-tracking technology. The company says the app now provides a "more precise measurement" of your sleep stages.