Mark-Paul Gosselaar announced the birth of his fourth child, a daughter named Lachlyn Hope, on Wednesday.
The new little bundle come into the world Tuesday and joins big brother, 16-month-old Dekker Edward. Lachlyn and Dekker are Gosselaar's children with wife Catriona McGinn.
Gosselaar is also father to 8-year-old Ava Lorenn and 10-year-old Michael Charles from a previous relationship.
"So in love with our new baby girl, Lachlyn! Born last night 2/17 Mum and baby are healthy and happy. 2 boys, 2 girls, too perfect!" Gosselaar wrote on Twitter Wednesday.