Filming Independence Day: Resurgence caused Liam Hemsworth to have nightmares about aliens.
The 26-year-old plays Jake Morrison in the sequel to 1995's Independence Day, where he helps Jeff Goldblum, who reprises his role as tech wizard David Levinson, to fight off an alien invasion.
And the Australian star admits that he got so into his role that he ended up fighting off aliens with Jeff in his sleep.
"My work really affects my home life and I had terrible nightmares that Jeff and I were being attacked by aliens," he tells U.K. chat show host Graham Norton. "I actually had dreams that we were running away from aliens. We weren’t fighting them, just running away!”
Being chased by aliens in his sleep wasn't the only hardship Liam had to undergo for the movie, as he previously admitted that toilet breaks proved quite the struggle when he was wearing his spacesuit costume.
"The space suits were tough," he told SciFiNow magazine. "It takes a long time to put them on and take them off, so bathroom breaks were pretty far in-between."
Interviewed alongside Jeff, 63, on The Graham Norton Show, the star also explained he had received excellent training for his action roles in dystopian fantasy franchise The Hunger Games and now Independence Day by fighting with his elder brother and fellow Hollywood star Chris, 32, as a child.
"Our childhood rivalry was a bit vicious - a bit like The Hunger Games actually," he explains. "We had a few incidents with weapons ...we were very likeminded, very stubborn and would often get into arguments and because I was so much younger and smaller I had to use weapons to fight."
The brothers' fights were so fierce Liam admits that on one occasion he picked up a kitchen knife and threw it at his sibling.
"So one day when I was about five we had a fight in the kitchen about using the toaster, or something, and I picked up a kitchen knife and threw it at his head and the handle hit him in the forehead," he said.
However, the star jokes that he didn't mean to harm Chris, adding, "I could have hit him with the other end if I'd wanted to - it was just a warning shot!"
U.K. TV viewers can see Liam and Jeff's full interview on The Graham Norton Show on BBC One on Friday (10Jun16).