The Waltons' Homecoming premieres Sunday on The CW
the waltons homecoming
Credit: Tom Griscom/The CW

When Richard Thomas found out that The Waltons: A Christmas Story was being remade 50 years after he starred in the TV movie, he felt protective of the film that launched his career.

"You have a sense of ownership, so when they call you and say, 'Well, we're doing a new one. It's all new people,' your first reaction is, 'Oh, no. Time to pass it on. Too bad,'" Thomas, 70, tells PEOPLE in this week's issue. "And then you realize, be proud and happy that it's considered a classic. I think it's wonderful that somebody else is going to have a chance to make that part their own." 

Thomas starred as John Boy in the 1971 original about a rural Virginia family, which later inspired the Waltons TV series that aired on CBS for nine seasons from 1972-81. Now, he'll serve as the narrator of the remake, The Waltons' Homecoming, which premieres Sunday on The CW.

For more from Richard Thomas, pick up the latest issue of PEOPLE, on newsstands now.

the waltons homecoming
Credit: Tom Griscom/The CW

On the beloved show, Thomas played one of seven children. In real life, Thomas is himself a father of seven. He shares son Richard and triplet daughters Barbara, Gwyneth and Pilar with ex-wife Alma Gonzales, and has a son, Montana, with wife Georgiana Bischoff, who has two daughters, Brooke and Kendra, from previous marriages.

"It wasn't planned," he says of the similarities. "I guess seven is my number."

the waltons

As the Emmy winner looks ahead, he says retirement isn't in his near future. "One of the beautiful things about acting is if you're lucky enough to be able to keep working your whole life, there are roles that will sustain you from childhood right up until ancient supporting character man," he says.

"Especially in the theater, there are great roles in all those categories," he continues. "So as I keep chugging along, there's always just one more thing to do, and I love it so much. When your work is also your pleasure, it's hard to think about retiring."

The Waltons' Homecoming premieres Sunday at 8 p.m. ET on The CW.