'IT Chapter Two' bosses aimed for an "unusual choice" when it came to casting.
The horror sequel to the 2017 blockbuster - both based on Stephen King's iconic novel - introduces adult versions of the Losers Club with the likes of Bill Hader and Jessica Chastain joining the cast, and producer Barbara Muschietti has opened up about the process.
She told Digital Spy: "I think, you know, a part of it was convincing our partners, the studio, that we wanted to cast people that were an unusual choice - although they were so obvious, because they looked so much like the original Losers.
"And that was 100% our number one goal - apart, of course, from them being great actors. But we needed to have people that looked exactly like the kids."
Isaiah Mustafa was chosen to play the adult Mike Hanlon - whose younger version was played by Chosen Jacobs - and Muschietti admitted they put him "through the wringer" when it came to his auditions.
She added: "So, you know, we put Isaiah through the wringer pretty much, because we had him audition - I don't know how many times - six or seven times.
"He was on his way to the airport to get on a flight and get married when we called him and asked him if we could do more one round. He turned around, went to the casting office, did it, and then he got the part. So, yeah."
Meanwhile Chastain - who played Beverly Marsh as an older version of youngster Sophia Lillis' character - director Andy Muschietti left her "drowning in blood" on set because he is a perfectionist.
She appears in one scene in which she is drenched in 4,500 gallons of fake blood and she has now revealed that she had to shoot the scene multiple times, each time getting cleaned up and starting afresh, because Muschietti wanted it to be flawlessly fear-inducing so it had the biggest impact on the audience.
Chastain said: "Everything is much easier than making a movie with Andy Muschietti. He's funny but he's also impossible because he does 60 million takes in the mud, in the slime, in the blood, every take you have to start again. It was a lot, I was drowning in blood."