Ariana Grande has heaped praise as he celebrates 20 months sober.
Frankie Grande, 36, marked the feat over the weekend and his little sister has honoured him for sticking the course.
'Man, I love u @FrankieJGrande. happy. twenty. months. been staring at this draft n deleting bc (because) everything i write makes me cry," she wrote on social media. "just know i think you're a superhero and u make me v. proud. everyone knows how hard this is and how strong you've been. congratulations and thank god (sic).'
Frankie previously credited his sister's late ex-boyfriend Mac Miller with helping him seek help for a substance abuse issue.
Rapper Miller died last year (18) and following the tragedy, Frankie paid tribute to his friend on Twitter, writing: "He was the reason I went to the rehabilitation centre where I was detoxed safely from all of the drugs, alcohol and medications I was taking, when I couldn't imagine living without them."
Announcing his continued sobriety, Frankie wrote: "Over the past 20 months i have felt loss but i have also felt love. i felt joy but i also felt grief. but the bottom line is ... i felt. and that is such a gift (sic)."
The reality TV star's sobriety has been tested of late following his split from married couple Mike Pophis and Daniel Sinasohn, his boyfriends of four months.
"'I'm super grateful for my last relationship. I grew so much in it, and at the same time, it wasn't working out anymore," he recently revealed. "I'm super glad that we decided to end things amicably. And that we can all remain friends... That's the important thing."
The news comes at a great time for Ariana - she is dominating charts around the world with her new album Thank U, Next, which debuted at number one in the U.K. and U.S. over the weekend.