Facebook CEO Mark Zuckerberg is asking his employees to stop being ignorant and racist (my words, not his).

In an internal memo obtained by Gizmodo, Zuckerberg said he was disappointed by the “several recent instances of people crossing out ‘black lives matter’ and writing ‘all lives matter’ on the walls at MPK.” MPK, one of Facebook’s buildings in Menlo Park, Calif., has a wall reminiscent of the early days of Facebook for employees to write their thoughts.

Here’s the memo, courtesy of Gizmodo:

Facebook is a notoriously white place. In the U.S. last year, Facebook hired 36 black people and 73 Hispanic people, compared to 603 white people, according to its 2014 EEO–1 report. In total, only 2 percent of Facebook’s workforce is black, 3 percent of it is Hispanic and — no surprises here — 55 percent of Facebook is white.

In addition to the fact that this is terrible, it’s especially effed-up timing given that it’s Black History Month and given the fact that several African-American students from the San Francisco Bay Area are planning a trip to Facebook tomorrow.

As Zuckerberg noted, Facebook is investigating the incidents and is encouraging employees to participate in an upcoming town hall at Facebook to learn what Black Lives Matter is all about. I’ve reached out to Facebook, but the company declined to comment further.