Kaitlin Olson and Rob McElhenny welcome another son

(CBS News) "It's Always Sunny in Philadelphia" co-stars Kaitlin Olson and Rob McElhenney welcomed their second son on Thursday.

Pictures: Celebrity babies

Leo Grey McElhenney was born at 1:15 a.m. at their Los Angeles home, the couple told People.

"We are overjoyed," Olson said in a statement.

The newest McElhenney weighed in a 8 lbs, 5 oz. He joins the couple's other son, 19-month-old Axel Lee.

Olson, 36, and McElhenney, 34, married in Malibu, Calif., in September 2008.