The Constant Gardener star, who is married to James Bond actor Daniel Craig, teamed up with Jeremy Renner for the action thriller but she admits the shoot was tougher than she anticipated - and she often called home to share her terror.
She tells Britain's Stylist magazine, "Actually, the stunts were terrifying. There were weeks spent on the back of a motorcycle, with Jeremy riding it, jumping over intersections and down staircases, and jumping off bridges in harnesses and onto moving buses.
"It was a challenge. I was genuinely scared - I didn't have to do any acting at all when we did the action scenes! I would be phoning home saying, 'I'm terrified'. I'm sure it must have been safe, but it didn't feel it."