Miriam Margolyes has told adult 'Harry Potter' fans to grow up.

The 82-year-old actress played Professor Sprout in two of the movies based on J.K. Rowling's book series and Miriam has revealed she "worries" about grown-ups who are still obsessed with the stories because they are "for children".

During an interview with New Zealand's 1News, she explained: "I worry about 'Harry Potter' fans because they should be over that by now. It was 25 years ago and it’s for children. I think it’s for children. But they get stuck in it."

Miriam went on to reveal she often makes personalised videos for fans via the Cameo service and she is amazed by the requests from devoted Potter followers.

She added: "I do Cameos and people say, ‘Oh, we’re having a 'Harry Potter' themed wedding.’ And I think, ‘Gosh, what’s their first night of fun going to be?’ I can’t even think about it. 'Harry Potter' is wonderful and I'm very grateful to it but it's over."

Miriam previously admitted appearing in the movies didn't make her rich because she was only paid £60,000 ($68,000) to star in 'Harry Potter and Chamber of Secrets' and 'Harry Potter and the Deathly Hallows - Part 2' unlike main stars Daniel Radcliffe, Emma Watson, and Rupert Grint who were all paid seven-figure salaries.

She told the Metro newspaper: "I'm not very ladylike. I've got a ladylike voice and I think it's the contrast of saying C***face' in a very sweet voice that engages people. Anyway, I've made a lot of money out of it so I'm perfectly happy with that.

"I never made 'Harry Potter' millions. I think the three or four main people. I was only in two and I only got £60,000 for being Professor Sprout but I'm not grumbling. Now. I grumbled then but it made me very famous!"