• Zak took to Instagram Tuesday to pen down a heartfelt tribute to his father
  • Robin Williams died by suicide at the age of 63
  • Zak had earlier said his toddler son has been getting slowly introduced to his late grandfather

On the sixth anniversary of Robin Williams’ death, his eldest son, Zak, penned a heartfelt tribute to his father.

Zak took to Instagram on Tuesday to post the message.

"Dad, today marks six years since your passing. Your legacy lives on in your family and in those who carry your spirit within their hearts. We will continue to fight for what’s good in the world, for peace, and for connecting people instead of tearing them apart. Love you so much!" Zak wrote.

On Aug. 10, Robin’s daughter and Zak’s half-sister, Zelda, took to Twitter to explain the toll the day takes on her and also to reveal she would be taking a break from social media on the death anniversary.

"It's hard for me on regular, good days to remain the person expected to graciously accept the world's need to share their memories of him and express their condolences for his loss. As I've said in the past, while I am constantly touched by all of your boundless continued love for him, some days it can feel a bit like being seen as a roadside memorial—a place, not a person—where people drive past and leave their sentiments to then go about their days comforted their love for him was witnessed," she wrote.

Zelda went on to say that sometimes the outpouring leaves her "emotionally buried under a pile of other's memories instead of my own. After all, even roses by the truckloads still weigh a ton."

Robin died by suicide at the age of 63. His representative had told at that time the Oscar-winning actor “had been battling severe depression of late.”

Meanwhile, earlier this year, Zak had told People that his toddler son has been getting slowly introduced to his late grandfather.

"His mom [Olivia June] and I have certainly considered how we want to introduce my son's grandfather, my dad, into his life. Certainly through his movies and the cartoons that he participated in is a great way. My son, Mickey, points at a cel that we have in his room of my dad that has the genie from ‘Aladin,'” he told People.

"We hope that we can celebrate the positive elements and his works and films in a way that there can be appreciation and acknowledgment of him both as an entertainer, but also as a family man, and parent and grandfather to my son,” he added.

Robin Williams Robin Williams, photographed during a panel discussion about the now-defunct CBS show “The Crazy Ones” in Beverly Hills, California, on July 29, 2013. Photo: Reuters