Plus, find out why he was intimidated by OG Ghostbusters Bill Murray and Dan Aykroyd.
You worried for nothing, Ghostbusters fans!
Paul Feig, who directed hits like Bridesmaids and Spy before taking on the reboot of the beloved franchise, knows your -- arguably sexist, absolutely unfounded -- fears about his take on the 1984 classic, which stars Melissa McCarthy, Kristen Wiig, Kate McKinnon and Leslie Jones.
"It's funny. When people first heard that I'm doing an all-female Ghostbusters, I think they assume there's going to be a lot of dress shopping montages and trying on hats," Feig told ET.
"My only goal was to make this as kickass as I can and we have our ladies kicking major ghost butt," he added.
And kick ass, these 'Busters do. The mastermind behind the movie and his cast promise intense action, plenty of laughs and an adventure that everyone can enjoy -- that's why they're not worried about the so-called controversy.
"Oh my gosh, there's no side to this movie," McCarthy told ET on set. "Kids are going to love it. Adults are going to love it. Men, women, ghosts. I'm not discriminating against ghosts."
"It's the best underdog story," she added. "It's the greatest underdogs of smart academics and strange people who believe in what they believe in and come together and then you actually like save the world. I mean, who can't root for that?"
WATCH: 'Ghostbusters' Trailer Features Badass Ladies, Hunky Chris Hemsworth, and...a Slimer Cameo!
Diehard fans of the original can also rest assured knowing the film got the stamp of approval from the O.G. Ghostbusters: Bill Murray, Dan Aykroyd and Ernie Hudson will all appear in the film, and Aykroyd has called the new recruits "adorable, hilarious and badass."
Still, Feig says it was "intimidating" having Venkman and Stantz agree to cameo.
"First of all, I'm the lifelong fan of theirs, and the thought of getting to work with either one of them was such a dream," he said. "To have them come back to this franchise that they started, that wouldn't exist without them, it was intimidating at first...But then when they came, they were so open, and warm, and really just excited about the project."
"They love the four ladies and they love everything that we're doing with the movie," Feig concluded. "So, it was a joy to have them there."
Find out even more about the not-so-secret cameos, all the action and other secrets we learned on the set of Ghostbusters in the video below. (Spoiler alert: The slime is made from tapioca! And you can eat it!)