Facebook is running a new experiment that allows people to turn off select ads that they deem upsetting.

For now, the test is only being applied to Facebook ads from alcohol brands and marketers, or promotional content relating to parenting, reports Ad Age. The move marks the first time the social network has allowed users to selectively block certain topics. Facebook claims it will consider adding more options based on user reports.

“Those are the two most common topics,” Mark Rabkin, VP of core ads at Facebook, told Ad Age. “For families who experience the loss of a child, to continue to see ads about parenting and new baby stuff, that can be really upsetting.”

In general, Facebook users can customize their ad preferences in regard to their broader interests (as identified by the social network). Alongside its ad blocking test, Facebook is also updating the look of its ad preferences tool in order to make it easier to navigate.

As with most experiments, the test feature will be available to a handful of users, and could later be rolled out widely.

Facebook didn’t have the easiest of times implementing its ad experience updates back in August. The move essentially circumvented any ad-blocking extensions users had in place, much to the chagrin of the developer of one such plug-in: Adblock Plus. Initially, Adblock Plus managed to create a workaround for the update, but Facebook quickly updated its code to render the software useless.

The social network offered the following statement in its defense: “We’ve designed our ad formats, ad performance and controls to address the underlying reasons people have turned to ad blocking software. When we asked people about why they used ad blocking software, the primary reason we heard was to stop annoying, disruptive ads.”

It seems Facebook has now realized that in certain cases ad blocking should be permitted, and that simply offering sweeping customization options does not suffice.