"Once Upon a Time" castmates Ginnifer Goodwin and Josh Dallas are engaged to be married.

The costars, who met on the set of the hit ABC show, announced the engagement through an exclusive with PEOPLE magazine.

"We are so thrilled to announce our engagement and can't wait to celebrate with our friends and family, including our second family at 'Once Upon a Time,'" the couple said in a statement to PEOPLE. 

Goodwin, 35, and Dallas, 31, made the relationship public in April 2012.

"It hit me like a blinding light," Dallas said of falling for the "Big Love" actress. "I thought, 'I'm in trouble now.'"

He popped the big question on Wednesday. The pair have not yet announced a wedding date.

ABC's "Once Upon a Time" is now in its third season. Fittingly, Goodwin stars as the Snow White character, while Dallas plays the Prince.

"This season, for me," Goodwin told Rolling Stone in a recent interview, "I think is going to be about [creating] a character that can make it all work. Because clearly, I'm going to have to let go of certain qualities in order for my character to achieve what she needs to achieve."

Of her dual character, "She still is not able to let go of the guilt," Goodwin said. "At the end of last season, it was about trying to heal her heart, and I think we're going in this direction that her working on her relationships with other people is what's going to make that happen. It can't just be a solo journey."

The show featuring storybook characters such as Rumplestiltskin, the Evil Queen and Captain Hook has had solid ratings and already spawned a spinoff, "Once Upon a Time in Wonderland."

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