Jennifer Garner on the 'Beautiful Experience' of Reuniting with Mark Ruffalo for New Movie: 'Instant Comfort'

Jennifer Garner and Mark Ruffalo didn't have to work too hard to get back in the groove.

The longtime pals and former 13 Going on 30 costars reunited on the set of Ryan Reynolds' upcoming movie The Adam Project, where they play a married couple. Garner, 48, told Good Morning America that it was easy to get back in the rhythm with Ruffalo, 53.

"It was wonderful," she said of working with Ruffalo again. "We were playing a married couple and we just had this instant comfort and obviously there's just such a connection and a warmth. It was actually a really beautiful experience to revisit that relationship."

As for her 13 Going on 30 character Jenna Rink, Garner said she hopes she would "still be whimsical and have a little bit of fun."

"She would have to still have some 13-year-old in her," Garner said. "But, oh, gosh, I have to go back and watch this movie. It's so fun ... Is Poise still going? Is it all online? What's happening?"

Garner and Ruffalo previously celebrated their reunion by sharing selfies on Instagram.

"Reconnecting with an old pal," Ruffalo captioned a shot with Garner. "Anyone know where we can get Razzles in Canada?"

Garner also posted the same picture from her account, writing, "Wishing dust worked! And I got a perfect day with my old pal."

According to The Hollywood Reporter, The Adam Project finds Reynolds playing a man who travels back in time to get help from his 13-year-old self and find his dad — a brilliant physicist played by Ruffalo — in order to save the future.

Garner will play Reynolds' mom and Catherine Keener is set to play the villain who stole technology from Ruffalo's character.

The Adam Project marks the first time Garner and Ruffalo have reunited onscreen since their fan-favorite 2004 film.