AT&T's 5G E servicewhich is not actually connected to a new 5G networkwas launched in December. And competitors Verizon and T-Mobile arent impressed.

Verizon has promised to only label products 5G if the device is actually delivering improved performance equal to 5G capabilities.

We wont take an old phone and just change the software to turn the 4 in the status bar into a 5, Kyle Malady, Verizons chief technology officer, wrote in a post Monday.

T-Mobile also mocked the “5G E” upgrade by joking you could upgrade your phone to 9G by putting a sticky note on it, and now Verizon is openly rejecting AT&T’s tactics.

AT&T recently updated its phones to replace “LTE” with “5G E.” The phones are not actually connected to a new 5G network—5G E stands for 5G Evolution, a rebranding of the faster portions of LTE.