(L-R) Seann William Scott and Kat Dennings; Tim Allen. Photo: Disney/Raymond Liu; Disney/Mike Taing

Kat Dennings and Seann William Scott are getting candid about what it’s like working with their legendary costar Tim Allen.

Ahead of the Wednesday, March 19 season finale of their ABC sitcom Shifting Gears, Dennings and Scott spoke with PEOPLE about what Allen, 71, is really like on set. Before meeting the Toy Story actor in real life, Dennings, 38, knew from her years of working in Hollywood to keep her expectations in check.

“I have learned through experience that you just never really know how someone’s going to be, especially when they have such a long-running career,” she tells PEOPLE. “Sometimes they’re exactly what you think, sometimes they’re the complete opposite.”

Thankfully, in Allen’s case, the comedian proved to be “kind” and “welcoming” to everyone on set. “I was very happily surprised,” Dennings says.

The 2 Broke Girls alum also shared that Allen loves to make the crew and his costars laugh. “He has the funny bone of a 9-year-old boy,” she adds, noting that her TV dad often “walks into walls” and “bangs something and scares everybody.”

“He just has a blast,” Dennings says.

(L-R) Kat Dennings and Tim Allen on ‘Shifting Gears’.Disney/Raymond Liu

As for Scott, 48, working with Allen has been a special experience because he reminds the American Pie actor of his late father.

“He kind of reminds me of my dad, actually,” he says. “My dad passed away a while ago, you know, but even one of my brothers who loves the show sent me a text. He’s like, ‘Tim really reminds me of dad,’ and I was like, ‘Yeah, you know, it’s true. He does.'”

Beyond reminding him of his father, Scott was impressed by how genuinely “fun” Allen is when they’re working together.

(L-R) Tim Allen, Seann William Scott and Kat Dennings on ‘Shifting Gears’.Disney/Raymond Liu

“I think when you’ve had that much success, there’s a good chance somebody could come in and not be as fun to work with and maybe just be kind of a jerk,” Scott tells PEOPLE.

Instead, Allen is “just funny and always cracking jokes,” according to Scott. He adds, “He’s definitely a guy’s guy, you know?”

In the season 1 finale of Shifting Gears, Allen’s Matt finds himself in the tricky position of trying to stay neutral as his daughter Riley (Dennings) tries to decide between reuniting with her ex or forging a new path for her and her kids. ABC hasn’t renewed the comedy for season 2 yet, but Scott and Dennings are both eager to continue exploring their characters for years to come.