Katy Perry has said before that the inspiration for her song "Firework" came from a line in the classic 1951 novel On the Road, by Jack Kerouac. Now there is proof on the star's Twitter page!

Katy tweeted a link to the trailer for the upcoming film On the Road starring Sam Riley, Kristen Stewart, Amy Adams, Kirsten Dunst, Viggo Mortensen, Terence Howard, Garret Hedlund and Elisabeth Moss.

YES! This is going to be EPIC. The last quote in this trailer (which is from the book) inspired Firework. CAN'T WAIT:

The quote that Katy is referring to is the line of Sal Paradise, the main character of the book and film, played by Sam Riley. He says,

"The only people that interest me are the mad ones...the ones who are mad to live, mad to talk, desirous of everything at the same time. The ones that never yawn or say a commonplace thing, but burn, burn, burn -- like roman candles across the night."

On the Road details the adventures of Sal Paradise and his buddy Dean Moriarty as they travel across America in the late 1940s and is hailed as one of the most important novels of the 20th Century.

I agree Katy,  I can't wait to see this movie!