Chipotle’s structural shakeup continues. On Friday, the fast casual chain revealed that four of its 12 directors will not stand for board re-election at the company’s May 25 shareholder’s meeting.

The four directors, John Charlesworth, Patrick Flynn, Darlene Friedman, and Stephen Gillett, will remain on the board until the date, and didn’t give a reason why they were stepping down, only to state that it wasn’t a reflection of Chipotle and its business procedures.

Read Why Steve Ells is “More Confident than Ever” about Chipotle’s Future.

The company also stated that the moves were not influenced by activist shareholder Bill Ackman, who owns a 10 percent stake in the company with his New York-based hedge fund, Pershing Square Capital Management LP. Chipotle’s largest shareholder was the catalyst for Chipotle’s decision to add four new directors in December, including one from Pershing. This announcement also came two weeks after the hedge fund filed a prospectus with the SEC saying it could resell shares of Chipotle.

Charlesworth and Flynn, both former McDonald’s execs, were part of the board since 1999 and 1998, respectively. Friedman has been a director since 1995. Gillett joined in March 2015.

Chipotle, which is still fighting back from 2015 food safety issues, reported sales increases of 20 percent in December and 25.6 percent in January—a welcome change after a 2016 in which comps fell more than 20 percent. Shares rose 0.3 percent at $402.20 in afternoon trading on Friday.

Employee Management, News, Chipotle