Twitter has warned users to ignore a hoax suggesting an alternative colour scheme will appear in the app if they change their birth year to 2007.
Instead, users who fall for the scam will be locked out of their accounts because Twitter prohibits anyone under the age of 13 from using the site.
"Please don't do this," the company said via a tweet.
A spokesman for Twitter declined to confirm to the BBC how many people have succumbed to the hoax so far.
Within the EU, companies aren't allowed to create contracts of service with users under 13 without parental permission, according to the recently adopted General Data Protection Regulation (GDPR).
Twitter said that anyone locked out of their account erroneously could follow instructions in an email they should have received from Twitter or fill out an online form.
We’ve noticed a prank trying to get people to change their Twitter birthday in their profile to 2007 to unlock new color schemes. Please don’t do this. You’ll get locked out for being under 13 years old.— Twitter Support (@TwitterSupport) March 26, 2019
The hoax has been circulating for a few days, with one tweet promoting it having received nearly 20,000 retweets since it was posted on Monday.
BBC News found several users still posting tweets suggesting the birth-year change would activate a new design on the site.
Many appear to have been taken in by the hoax, though some have remained good-humoured about it.
Fell for the oldest trick in the book😂 changed my birth year to 2007 because of some tweet that said your twitter changes colour😅 and got suspended for some hours for being below 13 years😭— Magero Ronnie (@RonnieMagero) March 26, 2019
Others, however, have expressed dismay that they have lost access to their accounts.
In another recent scam, verified Twitter accounts were taken over by hackers and used to spread fake links offering free Bitcoin to users.