Lee DeWyze and Jonna Walsh

American Idol Season 9 winner Lee DeWyze is engaged, People reports.

The singer, 25, popped the question to model-actress Jonna Walsh on a yacht under a fireworks-filled sky at Disney World. "Jonna is a Disney freak," DeWyze tells the magazine. "They were playing love songs on the boat and I got down on my knee and asked her. I had a speech prepared, but it all went out the window so I just asked her. She started crying and I said, 'Is that a yes?'"

Watch music videos from Lee DeWyze

DeWyze and Walsh, 26, met last October when he cast her in his music video for the single "Sweet Serendipity." "We hung out and we went to a Lakers game on our first date. She's a Lakers fan and I'm a Chicago Bulls fan and we just clicked out of the gate," he said. "When you know, you know."

The couple plans to wed in the fall of 2012.

DeWyze just wrapped his first headlining concert tour earlier this month.