Twitter is trying to stifle Elon Musk. On Friday, the social media company unrolled a defense against Musk's unwelcome takeover bid,

introducing what is known as a poison pill to fend off Musk's $43 billion acquisition attempt.

The maneuver, formally called a shareholder rights plan, essentially allows current shareholders to acquire more stock in the company at a discount,

presenting Musk with a unwelcome "pill," meaning his shares would become diluted and his purchase would become far more expensive and less attractive.

It would require that Musk negotiate directly with Twitter's board on any attempts to buy the company.

The poison pill will take effect once a person or entity acquires 15% or more of Twitter's shares,

according to an announcement from Twitter's board of directors, which noted the plan will be in place until next April.

Musk, the largest individual Twitter shareholder, holds about 9% of company stock, but he has made an offer to buy the company outright.

With the poison pill plan now in place, Twitter is preemptively defending itself against the possibility of Musk upping his stake in the company.

"The poison pill puts a temporary roadblock in front of Musk going forward,"

Twitter adopts poison pill