Photos of Williams and Ohanian's rehearsal dinner show all the guests putting their phones into special pouches before entering the venue.
Eva Longoria was one of the celebrities in attendance seen carrying her phone inside the pouch, made by Yondr. It works by locking up whenever inside a designated phone-free zone, preventing any access to the device inside. If someone needs to make a call or answer a text, they have to physically leave the phone-free area and the case will unlock.
The pouches have recently been used by other big celebs like Dave Chappelle and Alicia Keys to prevent fans from recording their performances.
Serena and Alexis are expected to tie the knot today, but we may have to wait a while to see any photo evidence.