She may be new to Instagram and have disabled her comments, but that hasn't stopped her from shutting down trolls.
Attending the Toronto Film Festival over the weekend, on fan decided to draw a comparison photo of Julia Roberts in her Dsquared2 dress and the late Joan Crawford for their similar looks and ask followers 'who wore it better?'.
While the response was split, one user opted to attack the 50-year-old actress over her 'black ugly nail polish'.
Don't mess with Julia! Julia Roberts hilariously clapped back at a troll who called her manicure 'black' and 'ugly' on Tuesday
'Joan Crawford looks way better in my opinion more classic and refined and Julia is wearing ugly black nail polish!'.
And it wasn't long before Julia took to the social media platform to correct the user anniemagic11 over her manicure selection.
'@anniemagic11 It is in fact a navy polish with garnets crystals as a grounding accent,' she hilariously clapped back.
Standing up for her manicure! '@anniemagic11 It is in fact a navy polish with garnets crystals as a grounding accent,' she hilariously clapped back
Cheering Julia on! And it appeared as though fans were more than impressed with Julia's clap back, some even claiming she had made their week
'In case you would like to edit your comment from 'ugly black nail polish' to ugly navy polish with Garnet crystal. Just sayin',' she continued.
And it appeared as though fans were more than impressed with Julia's clap back, some even claiming she had made their week.
'@juliaroberts Okay this is the most fabulous takedown I think I've ever seen,' wrote one fan.
Love: Julia married cameraman Daniel Moder in 2002
Another one wrote: 'OMG Julia! You made my day, no no my week! You looked amazing and haters gonna hate. Yes you are just as iconic as Miss Crawford.'
Julia previously called social media 'sticky like cotton candy' but that didn't stop her from opening her Instagram account in June.
And although amassing over 108,000 followers in less than 24 hours (she now has 1.6 million), she's yet to follow anyone back.
Julia married cameraman Daniel Moder in 2002.
The loved up duo share twins Hazel Patricia and Phinnaeus Walter, 13, and Henry Daniel, 11.
Family: The loved up duo share twins Hazel Patricia and Phinnaeus Walter, 13, and Henry Daniel, 11