Deryck Whibley of Sum 41 Marries Ariana Cooper

After getting through a tough year together, Deryck Whibley and Ariana Cooper tied the knot in a beautiful ceremony Sunday in Los Angeles, multiple sources confirm to PEOPLE.

The couple exchanged vows under a flower-adorned altar at the Hotel Bel Air. “It was a chill and intimate ceremony,” says a source. “They had a violin play at the ceremony and the music was mellow, not typical rock that Deryck’s band plays, which was surprising.”

The bride stunned in a beaded, strapless ball gown, but wore white Converse sneakers underneath her dress. “She had the coolest kicks in town,” the couple’s wedding planner Christine Zohrabians of Fancy That! captioned an Instagram photo of the custom sneakers.

In April 2014, the Sum 41 rocker collapsed in his kitchen with a drink in his hand and was rushed by Cooper to the hospital, where doctors told Whibley his organs had failed from serious alcohol abuse.

Now sober and healthy again (the couple celebrated with glasses of apple cider alongside their cake!), the singer told Vice earlier this year he was “feeling better than I’ve ever felt.”

“There are so many exciting things now,” he said. “So many things are new for me. I’d never done anything sober Now there’s this whole world out there and things I’m realizing I’ve never done.”

This is Whibley’s second marriage. He and Avril Lavigne divorced in 2009 after three years of marriage.