Liv Tyler expanded her family by one on Wednesday, delivering her second child.

Tyler and her boyfriend, sports manager/agent David Gardner, welcomed their son together on Feb. 11, according to People.

"He's healthy and everyone is very happy," her rep told People. The baby may have arrived six weeks early though and will need to spend extra time in the hospital before going home, another source told the outlet.

The new baby joins his big brother Milo, whose father is Tyler's ex-husband Royston Langdon. Gardner also has a 7-year-old son, Gray, from a previous relationship.

"The Leftovers" star documented her growing belly on Instagram since confirming her pregnancy last September. She posted her last photo the day before giving birth at a New York City ballet event.

Tyler will return for season two of HBO's "The Leftovers" this summer.

 New York City ballet @dustinyellin

A photo posted by Liv Tyler (@misslivalittle) on Feb 10, 2015 at 5:41pm PST