Khloe Kardashian has officially changed her son's name.

The 39-year-old TV star and Tristan Thompson welcomed their son Tatum via surrogate in July 2022, and the celebrity duo have now decided to change his last name to Thompson.

Khloe initially gave her son Kardashian as his legal last name.

However, the name change was made legal earlier this week, when a Los Angeles county judge granted the request, according to documents seen by 'Entertainment Tonight'.

Khloe - who also has daughter True, five, with Tristan - decided to change her baby's name some time ago, but the switch has only recently been made official.

An insider told 'Entertainment Tonight': "When a baby is born and a name has not been chosen, something still must be submitted to the state, and the state will make a birth certificate for 'baby’ with the mother's last name if the couple is not married.

"Since then, Khloe and Tristan's son's name was legally made Tatum Thompson."

Meanwhile, Khloe previously admitted that she initially found it tough to develop a bond with Tatum.

The reality star confessed that it "takes time" to develop that connection.

During an episode of 'The Kardashians', she shared: "With True, it took me a couple days to be like, 'OK, this is my daughter,' and I was super into it - but just days.

"But with him, it's taken me, like, months. I love him and I love kids, but I definitely still don't have that complete bond. But you know, so many say it takes time."

However, in July, Khloe took to social media to post a gushing birthday tribute to her baby boy.

She wrote: "I am so proud to be your mommy. So proud of the love and laughter we have in our house. So proud of your beautiful, gentle, loving, infectious spirit. You light up every single room."