Actor Matt Damon produced a lighthearted moment at the Clinton Global Initiative last Tuesday, September 23 when he did his impression of the former president. The star of Good Will Hunting was part of a panel talking about initiatives for clean water and busted his Clinton impression out at an appropriate moment.

The Clinton Global Initiative is a conference organized by Bill Clinton, Hillary Clinton and Chelsea Clinton for the discussion of worldwide crises, and Damon was on hand to talk about water policy.

“We could definitely reach hundreds of millions of people,” Damon said, on bringing clean water to those without access to it. He then mentioned something Clinton had said to him earlier about increasing access to water, but switched to the former president’s Southern drawl before quoting him: “Just keep running those numbers up. Just run ‘em up.”

The topic was serious, but the audience evidently enjoyed Damon’s Clinton impression as they laughed along with him.

Damon reportedly mentioned the fact that made him pay attention to clean water initiatives, which was how every 21 seconds, one child under the age of 5 dies because of a preventable water-related disease. “That [statistic] arrested me the most when I first heard it,” he said.

For this reason, Damon co-founded Water.org in 2009 with Gary White, who was also on the panel at the Clinton Global Initiative. The two reportedly explained how lack of access to clean water and sanitation not only led to severe illnesses but also affected women, since they were usually targets of assault when they would pass water in public.

Damon stressed how important solving the water crises was globally by comparing it to the problem of AIDS or cancer. “We solved [the water problem] here in the West 100 years ago,” Damon said. “Just imagine if we solved AIDS tomorrow or cancer, and in 100 years, children were still dying by the millions—it’s really unconscionable,” he said.