The billionaire's recently updated name is a reference to a lawyer's error during a trial over Musk's "funding secured" Tesla tweets.
Nicholas Porritt, an attorney representing a group of shareholders who are suing Musk over his 2018 tweets, accidentally called Musk Mr. Tweet during the trial on Monday.
Porritt called the mistake a Freudian slip but Musk joked it was "probably an accurate description.
Now Musk says he can't get his old display name back.
Changed my name to Mr. Tweet, now Twitter won't let me change it back hetweeted on Wednesday, along with a laughing .
Twitter users have complained of having their names locked by the platform before.
In November, pop star Doja Cat turned to Musk for help after she accidentally locked her display name as christmas.
According to a November report in The Verge, users who were verified under Twitter's legacy policy weren't able to change their display names on the app. The rule was aimed at preventing impersonation after Twitter's verification caused havoc for some brands and public figures.
