Khloé Kardashian and Tristan Thompson’s son wasn’t originally given his father’s surname, according to a new report.

Tatum Thompson, as he is now known, was initially named Kardashian, TMZ reported Monday.

Sources also told the outlet that the 10-month-old was not his original first name either, though it is not known which moniker his mother had given him initially.

Eventually, the Good American co-founder changed her mind and had Tatum’s last name legally changed to Thompson.

Although no specific reasons were given for the name swap, it likely had to do with the fact that the former couple had been expecting their baby boy via surrogate when news broke that the NBA player had secretly impregnated Maralee Nichols.

Reps for the exes didn’t immediately return Page Six’s requests for comment.

Page Six broke the news in July 2022 that Khloé, 38, and Tristan, 32, were expecting a son — just a few months after his paternity scandal made headlines.

“Khloé has always wanted a little brother for [daughter] True and decided to go ahead with having the baby with the support of her family,” a source told us at the time.

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When the surrogacy news came public, Khloé and Tristan had not been communicating with each other outside of co-parenting their now-5-year-old daughter.

However, the dynamic between the exes since has changed so much that fans believed she and the serial cheater were back together — prompting her to lash out at her followers.

“Most [people] are stuck at believing the lies because it’s the narrative they want to fuel. Have fun…. Some things are just as simple as they seem,” she wrote on social media in May.

“A family member supporting another family member ESPECIALLY during a difficult time in life.”

The former couple put on a united front last week when they reunited for True’s pre-K graduation.

The “Kardashians” star and the athlete were photographed smiling together Wednesday as they attended a ceremony at their daughter’s school in Los Angeles.

Eyewitnesses also said the pair were seen having a friendly conversation and appeared to be on good terms.