Joseph Gordon-Levitt watched back-to-back Bruce Willis movies to play the actor's younger self in sci-fi film Looper.

The Dark Knight Rises star portrays a younger version of Willis' character in the time-travel story and Gordon-Levitt was determined to match the Die Hard star's voice and mannerisms.

Gordon-Levitt reveals he watched Willis' movies and transferred the audio to his iPod, while the Hollywood veteran also recorded his co-star's Looper lines to give him a helping hand.

He tells the Chicago Sun-Times, "The time travel story poses a unique challenge. Not only am I basing my character off someone else. I had to sit across the table and try to match Bruce...

"I watched his movies. I ripped the audio off his movies and put them on my iPod. Bruce also recorded himself doing my lines."

He also enjoyed hanging out with the movie tough guy to prepare for the part: "Just spending time with him was one of the most productive things. We'd hang out. Have a meal. He's such an icon. But once I met him, it didn't feel like that anymore."