"We can confirm that the One X+ will not receive further Android updates & will remain on the current version of Android," tweeted the official HTC UK Twitter account.
The company followed up these 140-character-limited remarks with a full statement to The Verge, saying that HTC One X will be joining its plus-sized, Tegra 3-equipped variant.
"We realize this news will be met with disappointment by some, but our customers should feel confident that we have designed both devices to be optimized with our amazing camera and audio experiences."
Stuck at Android 4.2.2
Because HTC One X and HTC One X+ aren't being updated to Android 4.4, both handsets are stuck with the older Android 4.2.2 Jelly Bean and the manufacturer's current Sense 5 overlay.
That means in addition to missing out on KitKat, these HTC phones don't have Android 4.3's Bluetooth Low Energy support for constantly syncing wearables like the Fitbit Force.
These hasn't affected all HTC One series phone owners. Android 4.4 KitKat has already rolled out to the company flagship HTC One phone, for example.
HTC thinks its customers should feel confident with the current software they have now, but a few are expressing their dissatisfaction on Twitter, reminding the company that HTC One X+ is only 14 months old.