Dame Julie Walters says when she heard Mamma Mia! was getting a sequel, she worried it would be “awful”.
The British actress, who plays Rosie in the films, is back for Mamma Mia! Here We Go Again, alongside other stars of the original 2008 film.
Meryl Streep, Amanda Seyfried and Pierce Brosnan star in the sequel with new cast members Lily James and Cher.
Dame Julie told Good Housekeeping: “I couldn’t see how it could work and what they could do with us.”
She added: “My first reaction when my agent told me they were making Mamma Mia 2 was, ‘oh God no, it is going to be awful’.
“But the script was so good. I think it is fantastic. I think it is better than the first one.”
Mamma Mia!, based on the musical of the same name, made $615m (£466m) at the box office.
The sequel will follow on from the original plot, but will also feature flashbacks that see Lily James play a younger version of Streep’s character Donna.
Dame Julie said that a few things had changed since the first film, unsurprisingly that everyone looked “10 years older”.
“Everybody was holding in their stomachs when we met! Everybody looked great, I thought.”
‘Cher was heaven to work with’
There has been a lot of buzz around the addition of Cher to the film and her performance of ABBA song, Fernando, which features in the film trailer.
Walters said of working with Cher: “It was heaven having her there, she’s a really great girl. I’m a massive fan.
“I always loved her as a kid. She was great and she sings this song at the end which makes the hair stand up on the back of your neck.”
Talking about what she would work on next, Walters said she is not planning on slowing down her career any time soon – as she’s been offered so many good roles.
She said: “It has been so busy in the last couple of years. I wouldn’t do things for the sake of working, it’s just that great things have come up.
“I can’t not do Paddington and I can’t not do Mary Poppins. I keep getting offered great work. I wouldn’t kill myself over it, but it has been good.”