"Bill and Ted's Excellent Adventure" was released in 1989. A sequel called "Bill & Ted's Bogus Journey" followed in 1991.
The films starred Reeves and Alex Winter as the titular, time-traveling teen slackers.
Reeves, 46, told MTV News the original film's writers, Chris Matheson and Ed Solomon, have been toiling away on a screenplay for a third movie.
"I believe the writers are six weeks away from a draft," Reeves said Monday. "No pressure, guys!"
MTV News said Reeves talked about the project a bit last September, as well.
"When we last got together, part of it was that Bill and Ted were supposed to have written the song that saved the world, and it hasn't happened," Reeves said. "So they've now become kind of possessed by trying to do that. Then there's an element of time and they have to go back."