Robert Downey Jr. in "Iron Man" Credit: Paramount Pictures

Even superheroes have their limits.

While performing a stunt on the set of Iron Man 3 in Wilmington, North Carolina, August 15, Robert Downey Jr. "sustained an injury to his ankle," a Marvel Studios rep tells Us Weekly. "There will be a short delay in production while he recuperates."

The actor, 47, began filming the follow-up to the megasuccessful Iron Man 2 on May 23. Scheduled for a May 3, 2013 release, Iron Man 3 also stars Gwyneth Paltrow, 39, Don Cheadle, 47, Guy Pearce, 44, Sir Ben Kingsley, 68, and Rebecca Hall, 30. Weeks before production began, Hall replaced Jessica Chastain, 30, in the role of Dr. Maya Hansen.

Downey Jr. most recently suited up as Iron Man in May's super hero epic The Avengers, costarring Chris Evans, 31, Scarlett Johansson, 27, Chris Hemsworth, 29, Jeremy Renner, 41, and Mark Ruffalo, 44. It became the fastest film to gross $1 billion worldwide, and as a result, writer/director Joss Whedon, 48, is working on a sequel. The Avengers 2 is expected to hit theaters on May 1, 2015.