Well, that's one way to ring in the New Year! Jessica Alba and her husband Cash Warren spent New Year's Eve welcoming their newborn son into their growing family. The actress gave birth to her third child — an adorable baby boy — on Sunday, Dec. 31, and she took to Instagram on New Year's Day to announce the exciting news and share the first photo of her bundle of joy!

"Hayes Alba Warren 12/31/17 Best gift to ring in the New Year!! Cash and I feel so blessed. Haven and Honor are already obsessed with their new baby bro #familyof5," the 36-year-old wrote in the caption of a shot of little Hayes sleeping, showing off his full head of hair. So cute!

Jessica's hubby also took to Instagram to share another photo of their son. In the shot, the new father-of-three held his baby boy and looked down lovingly at him as he slept in his arms and Cash wrote an extremely touching tribute to his son in the caption.

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Hayes Alba Warren: You sure know how to ring in the new year! You showed up a few days early but we couldn’t be any happier. Your Mamma is the strongest woman I know … you’re so lucky to have her by your side. You have two amazing sisters who already adore you and I know you’ll be thankful to have them guide the way. On your first day of life, I promise to love you, to cherish you, and to provide you with a sandbox full of dreams to explore. Welcome to the family my sweet baby Hayes! 12/31/2017

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"Hayes Alba Warren: You sure know how to ring in the new year! You showed up a few days early but we couldn’t be any happier," the 38-year-old wrote. "Your Mamma [sic] is the strongest woman I know…you’re so lucky to have her by your side. You have two amazing sisters who already adore you and I know you’ll be thankful to have them guide the way. On your first day of life, I promise to love you, to cherish you, and to provide you with a sandbox full of dreams to explore. Welcome to the family my sweet baby Hayes!"

Back in July, Jessica announced her pregnancy with the help of her daughters — nine-year-old Honor and six-year-old Haven. In the adorable Boomerang video on Instagram, Honor held up a black balloon shaped like the number one, Haven held up a balloon shaped like the number two, and Jessica held up a balloon shaped like the number three as she held her baby bump.