Jennifer Garner, Mark Ruffalo talk reuniting 18 years after '13 Going on 30'

Mark Ruffalo and Jennifer Garner are just as shocked as fans that it's been 18 years since they last worked together, absolutely stealing our hearts in "13 Going on 30."

"It's kind of crazy," Ruffalo told "Good Morning America" Tuesday, reacting to the length of time since he last co-starred with Garner. He then jokingly suggested now might be a good time to make a sequel to their 2004 rom-com.

"Yeah," Garner chimed in. "We were thinking maybe '50 Going on 80.' Would that work?"

Ruffalo agreed, "And then in 10 years we can do '65 Going on 90.'" We could franchise the hell out of it."

It's clear the pair still have chemistry after nearly two decades, and they're putting that to use in their new Netflix film "The Adam Project."

In the film, out March 11 on Netflix, the two play a married couple named Louis and Ellie. They are parents to a son named Adam, with newcomer Walker Scobell playing the younger version and Ryan Reynolds playing the older version.

"We feel like the history of Matt and Jenna and all the sweet love that people give '13 Going on 30' really adds to the feeling of the movie," Garner teased, noting that it "feels like a continuation in a way."

Despite the fact that "The Adam Project" deals with time travel and other sci-fi themes, Ruffalo said it's an emotional ride.

"They were both crying. It really did pull their heartstrings," he said of how his daughters reacted to watching the movie, adding that it surprised him because they're "pretty tough."

Now that Garner and Ruffalo are cinematically reunited once more, they promise fans won't have to wait that long to see them together again.

"We won't go another 18 years, for sure. I mean, I'll just haunt you," Garner laughed. "You have to hire me for something."

"No, we're done. It's over," Ruffalo replied. "This is going to be a yearly thing."