Ben Affleck Is 'Very Serious' About Staying Healthy as He Celebrates One Year of Sobriety

Ben Affleck revealed in October 2018 that he had completed a 40-day stay at a treatment center for his battle with alcoholism

Ben Affleck is focusing on his health as he celebrates a major milestone in his sobriety.

The actor, who revealed in October 2018 that he had completed a 40-day stay at a treatment center for his battle with alcoholism, officially marked one year of being sobriety earlier this month. A source previously told PEOPLE that Affleck is “in a great place both in his recovery and life,” and an insider adds in this week’s issue that the actor is working hard to stay that way.

“He is very open about how challenging it is for him and works on his sobriety daily,” the insider says. “Ben thinks of alcoholism as a disease—you shouldn’t be ashamed of a disease.”

Affleck is “very serious about his sobriety. It’s definitely not easy for Ben,” the insider adds.

He’s also been spending quality time with his family, including his and Jennifer Garner‘s three kids Violet, 13, Seraphina, 10, and Samuel, 7.

“They both take their job as coparents very seriously,” says the insider of the former couple, who finalized their divorce late last year. “While sober, Ben is able to spend more quality time with the kids. It’s exactly how Jen wants things to be.”

“The kids have had a great summer,” adds the insider. “They have sleepovers at his house, and he takes them out for fun activities.”

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Affleck entered rehab for the third time last year on Aug. 22, after Garner, 47, was seen driving the Justice League star to a treatment center, PEOPLE confirmed.

He stayed at the center, with only brief breaks to work out at home and attend business meetings, until October when he broke his silence about his treatment in an emotional statement on Instagram.

“This week I completed a forty-day stay at a treatment center for alcohol addiction and remain in outpatient care,” Affleck revealed in the Oct. 4 post. “Battling any addiction is a lifelong and difficult struggle.”

“Because of that, one is never really in or out of treatment. It is full-time commitment,” he wrote. “I am fighting for myself and my family.”