Stiller, who plays Derek Zoolander took to Instagram to reveal that Arnold would portray his on-screen son in the movie, reported Aceshowbiz.
Stiller, 49, shared a picture of him and Arnold in a red car. "Meet @cyrusarnold. Son of Derek. #Zoolander2," he captioned the image.
Shortly after Stiller posted the photo, Arnold posted the screenshot of the photo on his own Instagram account and captioned it, "It's out!!! I am playing Ben Stiller's son in 'Zoolander 2'!! So happy to share the news with all of you!! #zoolander2 #derekjr."
Besides Stiller, the film features Owen Wilson who reprises his role as Hansel, Derek's best pal, Christine Taylor who portrays Derek's wife, and Will Ferrell who returns as Mugatu. Kristen Wiig and Penelope Cruz are additionally set to make appearances.