YouTube is enacting its own bit of gun control.

One month after the mass shooting in Parkland, Florida, and five days before the planned March For Our Lives, the world’s top video site has tightened its policy regarding firearms. Thanks to the changes, YouTube will now prohibit several types of content, including videos that sell firearms, feature certain accessories, or teach viewers how to manufacture their own guns.

Videomakers who show intent to sell guns or link to sites that sell them will now run afoul of YouTube’s content guidelines. Many of the new restrictions cover accessories, such as high-capacity magazines and devices that allow semi-automatic weapons to fire at fully-automatic rates. One of the best-known examples of that latter category is the bump stock, which was employed by the shooter who perpetrated last year’s massacre in Las Vegas. After that tragedy, YouTube placed restrictions on bump stock videos; the site’s new guidelines are built on top of that foundation.

“We routinely make updates and adjustments to our enforcement guidelines across all of our policies,” reads a statement from a YouTube spokesperson. “While we’ve long prohibited the sale of firearms, we recently notified creators of updates we will be making around content promoting the sale or manufacture of firearms and their accessories, specifically, items like ammunition, gatling triggers, and drop-in auto sears. We will begin enforcing these new guidelines next month. We recommend creators take a look at our Help Center and review their own content during that time.”

While the new guidelines will prohibit some videos from being uploaded to YouTube, they will not affect the video site’s monetization policies.