Two little girls showing love and appreciation for their American Girl dolls is going viral.

Wisconsin mom Katie Nachman posted a video of her daughters’ reactions to their dolls to Facebook. For Nachman, the dolls, which are black, are about more than just playtime; they’re a tool to teach her daughters about diversity.

The video shows her daughters explaining why they like their dolls, mentioning things like their clothes, hair, and eyes. It has been viewed more than 3 million times.

“[I]t demolishes the expectation that in order to love someone, care about someone, be a friend or play with someone, the other person has to look like you,” Nachman wrote on Facebook. “[W]hite parents have an obligation to teach our kids about race from a young age, so they won’t grow up to perpetuate the cycles of institutional racism and injustice that are eating away at our country from the inside.”

Nachman says her daughters play with dolls of various ethnicities and love them all the same.

Read her full post below: