“Happy birthday my beautiful Jetty,” the actor wrote on Instagram on April 13. “I love you.”
He also posted a black and white throwback photo of the duo. John’s daughter, Ella Travolta, shared a snapshot of the siblings from their childhood days, as well.
“I love you Jetty,” she captioned the image. “Happy Birthday.”
Jett passed away at the age of 16 after suffering a seizure during a family getaway to Grand Bahama Island in 2009.
“We had a very full life, my son and I, 16 years,” John said during a 2015 interview with Entertainment Tonight. “We did travel the world and he saw every place by the time he was that age. But, you know, you plan on a life that’s a lot longer for your child and you always intend to go first. So, that’s the difference. Regardless of the full life we did live together, you know, you wanted a full life for him.”