Hilary Duff claps back at haters who called her kiss on the lips with 4-year-old son 'inappropriate'

Hilary Duff has a message for her haters.

The former Lizzie McGuire star recently took her 4-year-old son, Luca, to Disneyland, posting a sweet snap of the two sharing a peck in front of the entrance to the It's a Small World ride via Instagram on Monday.

WATCH: Hilary Duff: 'I Feel Like I Was Judged for Having a Baby Too Soon'

"Happiest happiest happiest happiest happiest happiest happiest happiest place on earth!" she captioned it. "We love you @disneyland."

Within minutes, however, Duff's comments section blew up with messages from people shaming her for being inappropriate. "Oh my... get a room!" one user wrote. Another called the photo "sick," while someone else said, "It's not recommended to kiss on the lips to our kids... it's not good for them."

See more photos of Hilary Duff through the years:

After reading the harsh (and somewhat hilarious) comments, Duff took to Twitter to send a message to the social media trolls.

"For anyone commenting that a kiss on the lips with my four year old is 'inappropriate,' go ahead and click a quick unfollow with your warped minds and judgment," the mother of one wrote.

Duff's fans were quick to reply to her message, letting her know they had her back. "There is nothing more beautiful than the love between a mother and a child," one user stated. Another added, "Everyone in the comments, stop giving other people advice on parenting. There are no rules."

WATCH: Victoria Beckham Under Fire for Kissing Daughter on the Mouth

Back in July, Victoria Beckham was criticized for a similar photo, which showed her kissing 5-year-old daughter Harper on the lips during a mother-daughter pool day.

Hear more on what trolls had to say about that pic in the video below.