Microblogging website Tumblr will no longer allow adult content, chief executive Jeff D'Onofrio said in a statement Monday.

The change is policy is a major reversal for the ex-Yahoo company, which since being founded in 2007 has been known for tolerating explicit material.

"We've realized that in order to continue to fulfill our promise and place in culture... we must change," D'Onofrio said. "Today, we're taking another step by no longer allowing adult content, including explicit sexual content and nudity."

The ban, which begins on December 17, will cover "images, videos, or GIFs" depicting sex acts or showing "real-life human genitals or female-presenting nipples," according to the new guidelines.

"There are no shortage of sites on the internet that feature adult content. We will leave it to them and focus our efforts on creating the most welcoming environment possible for our community," D'Onofrio added in his statement.

The announcement comes just three weeks after the company's app was removed from Apple's app store when child sexual abuse content was discovered on the platform and "immediately removed," according to a statement Tumblr released at the time.

While D'Onofrio did not say whether the shift in policy was related to the episode, he noted Monday that "posting anything that is harmful to minors, including child pornography, is abhorrent and has no place in our community."

"We've always had and always will have a zero tolerance policy for this type of content," he added.