Ryan Gosling knew just what to get his "Barbie" director Greta Gerwig for her birthday.

According to the movie's verified Instagram account, the actor, who portrayed Ken in the hit film, sent Gerwig a flash mob in honor of her special day.

"As Kens know.... Sometimes the only way to express your feelings is through song & dance!," the caption on the video reads. "Ken Ryan sent these special Barbies and Kens to start Greta's birthday with all the feelings!!"

Gerwig, who appeared to be in a Pilates class, can be heard saying, "Oh my God" as she was surprised. The men and women danced to Gosling's song, "I'm Just Ken" and Dua Lipa's, "Dance the Night Away" from the film's soundtrack.

At the end the group yelled, "Happy birthday, Greta!"

Gerwig, appeared to get emotional, called it "beautiful" and gave out hugs to the flash mob members.

Moviegoers also gave her a gift.

In less than the month, the film has already raked in $1 billion at the global box office.