U.S. Education Secretary John King told charter school leaders Tuesday that it was time to think about whether their discipline policies are giving students the help they need.

His speech reflected a movement that’s been underway for a while: The re-examining of the “no excuses” discipline that has defined the country’s highest-profile charter schools.

“In rethinking discipline, charters also have the opportunity to lead the way on equity,” he said. “The students who are most likely to be suspended and expelled are students who we already fail too often.”

As the co-founder of the high-performing Boston charter school Roxbury Prep, King himself built a school around no-excuses ideas. As he explained to Chalkbeat’s Elizabeth Green in 2012, his school was relentless about making sure students adhered to its uniform policy and other rules in an attempt to create a stable learning environment and to set students up for professional success.

“You’re going to be accountable, and I would much rather you learn that lesson with me here than out in the world when you’re dealing with the way in which the world is going to treat that,” said King, who also helped lead the Uncommon Schools charter network. (We dove deeper into King’s thinking, and the emotional debate about no-excuses discipline, in this March story.)

At many charter schools, such strict discipline has also meant high suspension numbers. In New York, where King served as state education commissioner, a number of charter networks have made changes in a bid to reduce suspensions.

“Today, with the benefit of all that we’ve learned over the last 20 years, the leaders of Uncommon are rightly rethinking discipline,” King said Tuesday, adding that schools in that network now turn more often to counseling, mentoring, and support groups for students. But, he said, “We did not do it fast enough.”