Charlie Sheen became a grandpa on July 17 after his oldest daughter Cassandra Estevez gave birth to a baby girl named Luna. Credit: Jason LaVeris/FilmMagic

Charlie Sheen is officially a grandpa! The Anger Management actor's oldest daughter, Cassandra Estevez, welcomed her first child with husband Casey Huffman on Wednesday, July 17, he told TMZ.

Estevez, 28, who is Sheen's daughter with high school sweetheart Paula Speert, gave birth to a baby girl named Luna. "It's impossibly a most wondrous day," Sheen, 47, told TMZ of becoming a grandfather. "My bucket list is a thimble!"

Sheen confirmed his daughter was expecting her first child during an appearance on The Late Show With David Letterman in January. "Me as a grandfather, Dave . . . I don't know. It's like the world's going to crack in half," he joked. "It's fabulous. It's just not a title I'm ready to adopt."

Sheen is also dad to daughters Sam, 9, and Lola, 7, with second wife Denise Richards, and 4-year-old twin sons, Bob and Max, with third wife Brooke Mueller. When Letterman asked the actor if he thought he'd be a good grandpa, Sheen quipped, "Well, yeah, because you can leave the kid!"