The spouses of nine years welcomed their third child and first son, Hayes Alba Warren, on Sunday, Dec. 31, Alba announced on Instagram Monday alongside the first photo of her baby boy shared to social media.
“Hayes Alba Warren 12/31/17 Best gift to ring in the New Year!!” wrote the actress. “Cash and I feel so blessed. Haven and Honor are already obsessed with their new baby bro. 👶🏽💙 #familyof5”
Warren chimed in on Instagram too, sharing a photo of himself gazing down at his son alongside a beautiful message that read, “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,” he added. “You have two amazing sisters who already adore you and I know you’ll be thankful to have them guide the way.”
Want all the latest pregnancy and birth announcements, plus celebrity mom blogs? Click here to get those and more in the PEOPLE Babies newsletter.
RELATED VIDEO: Pregnant Jessica Alba Says Having a Boy Is “Gonna Be a Whole Situation”
Warren continued in his post, “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.”
“@cash_warren and I are officially going to be outnumbered #babyonboard #herewegoagain 👶🏼🤰🏽#blessed🙏,” she captioned the post.
In late October, the actress and Honest Company co-founder revealed in another cute clip with her daughters that the baby on the way was a boy, showing the girls pulling on a string to release blue confetti from a suspended box.
Alba has been open about the excitement she and Warren, 38, feel about adding a little boy to their family. During a late-October visit to by The Rachael Ray Show, the Dark Angel alum joked she was looking forward to having “someone to love me more.”
“When [Cash] comes home, [Haven and Honor are] like, ‘Daddy!’ It’s like a party,” she explained. “When I come home, they’re like, ‘Oh, hey Mom.’ I’m like, ‘I do everything for you! I cook, I do all the things!’ ”
Earlier that month, the star said on The Tonight Show Starring Jimmy Fallon that the family was “super stoked” and that having a son was “gonna be a whole situation.”
FROM PEOPLETV: Katherine Heigl Introduces Baby Joshua
In early November, Alba debuted a new line of Honest Company seasonal diaper prints for winter, saying in the accompanying reveal video, “What’s so exciting about this winter diaper reveal is that this will be the diaper [print] that the little baby in my tummy will be wearing.”
And although the new baby’s sex is a nice bonus, what Alba was most looking forward to about caring for an infant one more time has everything to do with those first moments of new motherhood.
“Cuddling!” she told PEOPLE in August of her most-anticipated activity once her newborn arrived. “Cuddling babies are the best.”