The prank that made Bruce Willis lose his Die Hard cool

Justin Long managed to prank his co-star Bruce Willis while they were filming Die Hard 4 in 2007, he has revealed in an interview with People TV. Photo / Getty Images

It takes a lot to rattle Bruce Willis, but that's exactly what Justin Long managed to do on the set of Live Free or Die Hard.

In an interview with People TV, Long recalled how he pranked Willis while making the 2007 movie, leaving the action star "f***ing panicked" and yelling for help.

As Long and Willis prepared to film an intense car chase scene, Willis advised his younger co-star, "You're going to want to have some Dramamine (motion sickness medication) because it's going to be a bumpy ride."

Long decided to pass on the medication and Willis replied, "All right, don't say I didn't warn ya."

An idea popped into Long's head, and he asked one of the personal assistants to bring him a cup of oatmeal without Willis seeing.

"I set it aside, and when he wasn't looking I picked up the cup, and I took a big gulp, and I kept it in my mouth" Long told People TV.

"We finished the take, and the camera guys kept rolling because they knew I was going to do a bit. Bruce goes, 'How you feeling kid?'"

And that's when Long played his prank.

"I threw up all over myself, the oatmeal," he said.

"I've never seen John McClane panic because he doesn't panic in the movies, but he f***ing panicked!" Long said.

"We couldn't get out of the car, so he started rolling down the windows going, 'We got to get out, we got to get out!'"

Well played, Justin, well played.