Upgrade to Park Hopper At Gate?

[Disdude]

We bought my stepson and his family one day/one park Southern California Resident Disneyland passes. They are wondering if it is possible to upgrade them at the ticket sales booth when they get there to include the park hopper option. Any reason they cannot?

[2Epcot]

As far as I know, any type of ticket should be able to be upgraded at the ticket booth.

[Disdude]

Awesome! Thanks