Gwen Stefani is feeling cool about her son’s new chapter.

The No Doubt singer celebrated her and ex-husband Gavin Rossdale’s son Zuma officially becoming an adult, ringing in his 18th birthday with a heartfelt video that highlighted the teen’s musical abilities. 

“I cannot believe u are 18 today!!” Stefani wrote on Instagram Aug. 20. “Watching u grow into the sweetest + most talented young man has been one of the greatest gifts of my life. we love u soooo much Zuma.”

Alongside the sentimental message, the 56-year-old—who also shares sons Kingston, 20, and Apollo, 12, with Rossdale—posted a montage of Zuma through the years, set to the sounds of the 18-year-old himself strumming a guitar and singing Zach Bryan’s song “Dawn.” And Stefani made sure to show just how much her son had grown up, transitioning the clip into a video of him as toddler playing a kid’s guitar and loudly singing “Twinkle, Twinkle, Little Star.”