Credit: Bruce Glikas/FilmMagic

Mamma mia!

Meryl Streep's older daughter, Mamie Gummer, said "I do" to Ben Walker over the weekend, a source confirmed to Us Weekly.

The Off The Map star, 27, wed Walker, 29, at her family's Connecticut estate. Around 150 wedding guests celebrated with the newlyweds, including Claire Danes, Tracey Ullman and Laura Linney, a source told Us.

The actress got engaged to theater actor Walker in Oct. 2009. "My mom loves him," she gushed to Us at the Whitney Museum of Arts Gala in New York two days after the proposal.

Her beau even "surprised" her with a custom-made ring. "He did it on one knee!" she said.

Gummer is the second oldest of Streep, 62, and sculptor hubby Don Gummer, who have four kids.