Sarah Michelle Gellar is paying tribute to her on-screen dad.
The 40-year-old actress took to Twitter on Friday to honor Robin Williams, three years after his death.
RELATED: Pierce Brosnan Recalls Working With Robin Williams on 'Mrs. Doubtfire,' Shares Epic Flashback Photo
"We miss you everyday, but today especially. #RobinWilliams," Gellar, who played Williams' daughter on CBS' The Crazy Ones, wrote alongside a sweet black-and-white photo of the two.
Billy Crystal also remembered the late actor on social media, writing, "3 years later and words still don't come easily. Think of Robin today and smile."
WATCH: Robin Williams' Widow Pens Emotional Essay About Late Actor's Struggle Before Suicide
Williams died on Aug. 11, 2014, at 63 years old.
See how his daughter, Zelda, coped with his death in the video below.