Although Stephen King approved of the PG-13 approach to the adaptation of his fantasy epic The Dark Tower, the bestselling author hopes a potential sequel will venture into more adult territory.

REVIEW: Dark Tower Can't Measure Up to Stephen King's Novels

"I would love to see Roland [Idris Elba] on the beach with those lobster monstrosities, and I understand the rationale behind the movie, that it's PG-13," he told Collider. "I totally signed off on that. I think it's the right thing to do. I want as many people as possible to attend for all kinds of reasons; part of it having to do with the dynamic between the gunslinger and the boy because I think that's a father-son relationship, but I would love to see the next picture be R."

King said he thinks the chances for a more adult sequel are improved by the commercial success of recent R-rated genre films.

"For a long time, PG-13 was the safe spot to go and when pictures were R, studio executives would say 'Well, we know that this movie is going to make 20 to 30 percent less money because we’re going to exclude a market, a prime … part of the movie-going public. I think movies like Deadpool and Logan to some degree ..."

RELATED: The Dark Tower's Weird, Winding Road to the Screen

Whether The Dark Tower performs well enough to earn a sequel remains to be seen; the ambitious plans for the adaptation call for a movie trilogy, with each of the installment connected by a a season of a television series. Ahead of the film's nationwide release on Friday, it hovers at 19 percent on Rotten Tomatoes. CBR's Kristy Puchko calls the film "profoundly bland," writing, "Chiseled down to a lean-yet-tedious 95 minutes, it races through plot points, burning through minor characters who have little purpose before meeting grisly comeuppances, and leaving no room to feel the gravity of presumably big moments."

Directed by Nikolaj Arcel, The Dark Tower also stars Idris Elba, Matthew McConaughey, Abbey Lee, Katheryn Winnick, Fran Kranz, Claudia Kim and Jackie Earle Haley.