Among the many, many features of the new Galaxy S5 is something called “Download Booster.” en it’s enabled, the phone downloads large files (over 30MB) using both your -Fi connection cellular network at the same time, combining their bwidth for zippier downloads.

But if you’re a U.S. customer running out to buy the phone when it goes on sale tomorrow, there’s only one carrier that seems intent on letting you use it: T-Mobile.

A report on Android lice noticed that the AT&T unit doesn’t contain the feature anywhere in the settings, nor an option to add it to the notifications shade. Firecewireless got confirmation from Verizon Sprint that they’re following suit.

happen to have both the AT&T Sprint versions of the Galaxy S5 in-house, sure enough, the download booster feature is missing from both.

So what of T-Mobile? It hasn’t been confirmed on a live T-Mobile version of the phone yet, but the company’s product page proudly lists the Download Booster as a key feature of the phone. The feature is missing from the product pages on the Verizon, AT&T, Sprint sites. In fact, the Q&A section of Verizon’s page confirms the carrier’s lack of support for the feature.