Rumi and Sir Carter are growing up fast.

In honor of their 4th birthday on Sunday (June 13), Beyoncé shared heartfelt birthday wishes for her twin son and daughter.

“What’s better than 1 gift… 2,” Bey wrote on her official website. “Happy birthday Rumi & Sir.”

Beyoncé and JAY-Z welcomed their twins on June 13, 2017. They have kept their lives mostly off social media, but in March, Bey shared some rare photos of her with her three children, including 9-year-old daughter Blue Ivy, enjoying a day at the beach. They dined at Nobu in Malibu and took a stroll on the sandy shore with their mother.

In a 2017 interview with Rap Radar, JAY-Z revealed how he and his wife choose the names Rumi and Sir. “Rumi is our favorite poet, so it was for our daughter,” he said. “Sir was like, man, come out the gate. He carries himself like that. He just came out, like, Sir.”

During the Grammy Awards in March, Beyoncé shouted out all her kids when she became the most-awarded female artist in Grammy history. The same night, she and Blue also won Best Music Video for “Brown Skin Girl.”

“It’s such a magical night, thank you so much. I know my daughter is watching,” said the proud mom while accepting the award for Best R&B Performance for “Black Parade.” “Two daughters and my son, they’re all watching. Blue, congratulations, she won a Grammy tonight. I’m so proud of you and I’m so honored to be your mommy, all of your mommy’s. Y’all are my babies, and I’m so proud of y’all.”