The cast surprised the audience with a rendition of "I Will Follow Him," before sitting down to share secrets from the set.
"I don't know if we've had a reunion at all, but it was really kind of extraordinary, because we've been doing a little bit of rehearsing and it was wonderful. It was really remarkable," Goldberg confessed, while her co-stars told hilarious stories about their auditions.
"I had no intention of singing. And then Mark [Shaiman] said, 'No, you're singing in this!'" Goldberg added, before sharing that she wasn't supposed to be in the movie at all. "It was Bette Midler's movie, and Bette couldn't do it, so she turned it down, and then I guess they went to 100 million people, and got to me."
While Sister Act's actual 25th anniversary took place in May, Goldberg celebrated last month as she greeted fans dressed as nuns at a movie theater in New York City.
See more on Goldberg in the video below.