Gwyneth Paltrow is celebrating her son, Moses.

The 48-year-old actress took to Instagram this week to share a sweet tribute to her son, who she shares with ex-husband Chris Martin, on his birthday. Paltrow shared two rare photos of Moses, who turned 15 on April 8. The first was a closeup that shows off just how much Moses looks like his famous parents, and the second was an action shot of the teenager skateboarding.

"Holy Moses I can't believe you are 15 today," Paltrow wrote in the post's caption. "You are the dreamiest, sweetest, most brilliant guy ever. I love you so much, you can't fathom it. Happy birthday you little shredder 💙."

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Earlier this year, during an interview for Jimmy Kimmel Live!, Paltrow opened up about how Moses and his older sister, Apple, have been coping with quarantine. She revealed that isolation has been "hardest" for Moses and that skateboarding has been an important outlet for him.

"What's great is that he's a skateboarder, so he can do a lot of solo, outside exercise and work on skills and tricks and stuff like that, but I think it's very hard to be 14 and ... it's tough on the ones that are still in the most intense developmental stages, I sort of observed," she explained (per People) during the January interview. "Like, my daughter is 16, she kind of knows who she is and she's got her friends. My son would have started high school in September. I think it's hard socially. I've also been amazed how adaptable kids are during this time and how agile they've been. Hats off to all these kids around the world who are just getting through it."