Meryl Streep is a first-time grandmother after daughter Mamie Gummer gives birth

Congrats are in order for Meryl Streep!

The Mamma Gramma Mia star is officially a first-time grandmother after her eldest daughter, Mamie Gummer, gave birth to her first child with fiance Mehar Sethi, Us Weekly reports.

The outlet reports that the newborn is a boy.

News broke last December that Gummer, 35, was expecting, just a few months after Sethi proposed during their vacation in Croatia.

In addition to Gummer, Streep also shares three other children -- Henry, 39, Grace, 32, and Louisa, 27 -- with husband Don Gummer.

Congrats to the happy family!

In more baby news, Andy Cohen appears to be loving fatherhood after welcoming his first child, son Benjamin, via surrogate earlier this month.