In the photo, Garner is seen dressed in a wedding dress alongside costar Mark Ruffalo while hanging from wires during the making of the romantic comedy.
“Harry and Meghan, if you’re looking for stand-ins @markruffalo and I are just hangin’ around,” she wrote.
Garner, 46, concluded the post with the hashtag #congratulationsharryandmeghan.
Harry and Meghan said their “I dos” in a fairytale ceremony in St. George’s Chapel at Windsor Castle on Saturday.
Meghan, who arrived at the chapel with her mother, Doria Ragland, was a beautiful bride as she walked down the aisle to wed her royal fiancé in an elegant service fit for a princess.
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The service was attended by close family and friends, including Queen Elizabeth, Prince Philip, Prince Charles, Camilla, Duchess of Cornwall, Prince William and Kate Middleton. Charles had a special role in the service, escorting Meghan down the aisle after it was confirmed that her father, Thomas Markle, couldn’t attend the wedding.