Everyone remembers Dick Van Dyke as the loveable chimney sweep Bert in “Mary Poppins”, but it’s a different bit part in the iconic movie musical that came at a cost.

In the above preview clip for ABC’s “Mary Poppins Returns: Behind The Magic — A Special Edition of 20/20”, star Lin-Manuel Miranda sits down with his predecessor and learns that the legendary actor had to essentially bribe Walt Disney in order to play banker Mr. Dawes Sr. in the 1964 film.

Related: Get A Behind-The-Scenes Look At ‘Mary Poppins Returns’

“I had to go to Walt and ask him for the part,” the 92-year-old reveals during the special, set to air Thursday. “I said ‘I’ll do it for nothing.’ I actually had to give him $4,000 — I paid him to do the part… and I’d do it again!”

Much to his delight, Van Dyke appears in the upcoming sequel “Marry Poppins Returns” alongside Miranda and Emily Blunt, who recently sang the Emmy winner’s praises in a clip released to People Magazine.

Related: Emily Blunt Sings ‘A Whole New World’ With Her ‘Mary Poppins Returns’ Co-Star Lin-Manuel Miranda

“You spend five minutes with Dick Van Dyke and you are more alive than you were,” laughs Miranda. “He has more energy at 91 than I ever have in my life, and I’m not an un-energetic person.”

“You feel like you’re not doing enough in your life,” Emily says of the TV and film icon. “The energy and the spirit behind the eyes is… just extraordinary.”

“Mary Poppins Returns” hits theatres December 19th.