During her lifetime, Joan Rivers spoke highly of many of her fellow comedy stars, but there was one actor she wasn’t shy about saying she didn’t like—and that was Ben Stiller.

The “Night at the Museum” star spoke with Howard Stern on Wednesday and revealed that he and Rivers had contentious relationship that was never resolved before her death last year.

Stern, who had heard about Rivers’ distain for Stiller asked the actor about the late comedy star.

“She had a thing about me. She didn’t like me,” Stiller told Stern.

But from his side of things, he explained, he never understood why there was an issue.

“I never had an interaction with her,” Stiller insisted. “I didn’t understand why she didn’t like me – I mean I can understand that someone doesn’t like me, whatever… You’re allowed to have your opinion, but she had a thing because she was friends with my parents.”

Stern revealed to Stiller that Rivers had told the radio host she was offended after Stiller seemingly snubbed her on a red carpet. Supposedly Rivers was peeved because she felt Stiller should have said hi to her—especially given her friendship with his parents.

“First of all, I don’t remember that happening, but I am sure it did,” Stiller said. “And then I heard that there was a documentary or something and she [was asked] ‘what do you think of Ben Stiller?’ And she said ‘lucky’ or something… So then the beef started.”

The actor said there were still no hard feelings on his end and it felt good to discuss the drama and heal.

“But she was great and I feel bad that we never got to work that out,” he reflected. “My parents were really friends with her and spent a lot of time and worked with her and she had an amazing career.”

Click here to listen to Stiller’s chat with Stern.