Bill Hader has explained why he refuses to autograph Star Wars merchandise.

The Barry star served as a vocal consultant for the droid character BB-8 in 2015's Star Wars: The Force Awakens.

But during a recent appearance on the Happy Sad Confused podcast, Bill revealed that he has a blanket rule not to sign any Star Wars memorabilia.

"I used to sign stuff, and then one time I saw somebody and they had their kid come up to me to sign a BB-8 thing and it was three in the morning," he recalled. "I was leaving the (premiere of 2015 movie) Inside Out and then we went to an after-party thing and it was super late and this guy kept his kid up all night. (He was like), 'Go over there so he'll sign it so I can sell it online.' I was like, 'That's f**ked up.' And so now, I just kind of blanket, like, I'm not signing any of this s**t."

Elsewhere in the conversation, Bill insisted it was "very sweet" of director J.J. Abrams to credit him for BB-8.

However, he isn't convinced he really contributed much.

"I came in and did like voice stuff for it that didn't work," the 44-year-old stated. "Then, he brought me in later and said, 'Hey, do you want to do this.' It was like a talk box thing and then I did that. And the reason he hasn't had me come back is because anybody can do that... It's like a machine that you can operate."