T-Mobile announced today that it’s expanding its robocall-fighting Caller Verified feature to five new phones, including the Galaxy S10E, S10, and S10 Plus, along with the forthcoming LG G8 ThinQ and the LG Aristo 3.

Those phones join the Note 9, Galaxy S9, and S9 Plus in supporting Caller Verified, which displays a message that an incoming call is coming from a verified person, not a VoIP internet spammer. T-Mobile’s implementation relies on the STIR/SHAKEN authentication method (STIR: Secure Telephone Identity Revisited and SHAKEN: Signature-based Handling of Asserted information using toKENs). This method uses a certificate system that’s similar to how browsers confirm that a website is real to confirm that the call is coming from a real phone. (Caller Verified is different than some of T-Mobile’s other screening initiatives, like Name ID and Scam Block.)

STIR/SHAKEN isn’t a perfect solution to ending spam calls. It can’t tell you which calls are VoIP spam, only which ones it knows for sure aren’t. Limited device and carrier support mean that only a small subset of your contacts will likely be able to take advantage and actually show up as verified. (T-Mobile only works with those eight phones for now, and other carriers like Verizon and Sprint have yet to roll out support.) As Google’s new call screening for Pixel phones shows, this isn’t the only way to go about it.

Still, spam calls are an epidemic: there were over 26.3 billion robocalls last year in the US alone, so it’s good that something is being done. The FCC says it will “take action” if STIR/SHAKEN isn’t implemented this year. T-Mobile also announced today that it had managed to block 10 billion spam calls so far with its various anti-spam initiatives. Hopefully, the new Caller Verified features will finally help cut down on spam for good going forward.