Nickelodeon announced Monday that the upcoming TV movie based on the series — which coincides with the network’s 25th anniversary celebration of original creator-driven animation and will pick up where the show’s swan song left off in 2004 — will be titled Hey Arnold! The Jungle Movie and also feature the show’s original voice cast.

Most of the actors will be reprising their roles, including Dan Castellaneta as Grandpa, Francesca Marie Smith as Helga G. Pataki, and Tress MacNeille as Grandma. However, fans will notice that both Arnold and Gerald will sound different, probably because original voice actors Lane Toran (one of a few of actors who voiced Arnold over the show’s run) and Jamil Smith (Gerald) continued to age. Just a guess! Both men will lend their voices to other roles in the film instead.

In their place, Mason Vale Cotton (Mad Men) will take over as the titular boy with a football-shaped head, while Benjamin “L’il P-Nut” Flores, Jr. (Game Shakers) will voice Arnold’s best friend. They’ll be joined by fellow newcomer Alfred Molina who will lend his voice to the film’s villain, a notorious river pirate named Lasombra.Joining Cotton, Flores Jr. and Molina as newcomers to the universe will be Gavin Lewis as Eugene, Jet Jurgensmeyer as Stinky, Aiden Lewandowski as Sid, Laya Hayes as Nadine, Nicolas Cantu as Curly, Wally Wingert as Oskar and Stephen Stanton as Pigeon Man.