WILMINGTON, N.C. (AP) — A North Carolina college professor will retire amid criticism over his latest social media comments, which include calling the state’s governor “Massa Cooper.”

Mike Adams, a sociology and criminology professor at University of North Carolina Wilmington, will retire on August 1, Chancellor Jose V. Sartarelli said in a statement on Monday.

The latest controversy began in late May when Adams tweeted that he dined with six men at a six-seat table and “felt like a free man who was not living in the slave state of North Carolina.” He then wrote: “Massa Cooper, let my people go!”

An online petition calling for his firing has received more than 60,000 signatures, with celebrities even jumping into the mix. The school called his tweets “vile” expressions of free speech.

It wasn’t a first for Adams, who in 2016 posted an article about a student activist under the title “A ‘Queer Muslim’ Jihad,” The News & Observer reported at the time.

Faculty members at the University of Montana later opposed Adams’ visit to their school, writing that he had “a long record of mocking, demeaning and verbally attacking women, people of color, members of the Islamic faith and the LGBTQ community,” the newspaper reported.