Heidi Montag and Spencer Pratt just became an aunt and an uncle!

The Hills star's older sister Holly Montag, who briefly appeared on the reality series, gave birth to a baby boy named Isaiah Hawk on May 3, a source confirms to 'Us Weekly.' He weighed in at 7 lbs., 5 oz.

heidi montag

Holly and Heidi in 2008.

This is the first child for the 31-year-old and her husband, Richie Wilson, whom she married in September of last year.

Heidi previously revealed that her sibling's pregnancy had actually convinced her to hold off on having kids.

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“I was like, ‘I think I can put this off for a little bit because you look REALLY uncomfortable,'” she told 'Us.' “I’m three years younger. Maybe I can wait three more years to catch up."

Congrats to the new parents!