The Brit star is currently in Australia filming his role as King Caspian in The Chronicles of Narnia: The Voyage of the Dawn Treader, which is due for release next year (10).
But while filming scenes with co-star Skandar Keynes earlier this week (begs07Sep09) a sword stunt backfired - and Barnes had to receive treatment for an injury to his mouth.
He says, "We've been sword fighting. It didn't go quite according to plan - I've got a slightly swollen lip, because I got popped with the sword by young Skandar Keynes."