Keanu Reeves was already a big star when Speed came out in 1994, but it was this movie that really made him an action star.

Joss Whedon, who served as the script doctor on the movie, opened up in a rare interview about Keanu‘s involvement in making the film as successful as it was.

That included spending time with real SWAT officers, making his police officer character a bit more respectful towards others, and suggesting one critical line for the movie that’s still quoted by fans today.

Keep reading to find out more…

During his appearance on the 50 MPH podcast, Joss says that Keanu went above and beyond making Jack the best kind of action hero, in contrast to what was seen on the big screen at the time.

“[Reeves] talked about [doing research for the role by hanging out] with the SWAT guys and how they were unfailingly polite,” Joss recalled on the program. “[He said that] they’re only about defusing the situation, they call everybody ‘sir or ma’am.’ It was like click — that was it.”

He went on, saying that his “take on it was: He wasn’t a hot shot, he was a lateral thinker. He was going to do what felt right and have an odd approach to it, but generally speaking, it would work out.”

“That ‘sir or ma’am’ gave me so much, because bluster [in action movie heroes] was the order of the day and this was the opposite. He also said, ‘I don’t want to pull my gun.’ And I was like, ‘I don’t want you to either, but you kind of have to. … [The studio is] not going to let you not pull your gun.’”

On top of the prep Keanu did, Joss also revealed that he was behind the very quotable “Pop quiz, hot shot.”

The line is uttered by the late Dennis Hopper, who played disgraced cop Howard Payne.

Sandra Bullock, Jeff Daniels and Succession‘s Alan Ruck also starred in the movie.

Find out which other action movie Keanu almost starred in.