Us Weekly revealed that the 39-year-old actor wants to do something very special when the pair exchanges vows.
Pratt, 39, said at The Lego Movie 2: The Second Part in Westwood, California, that they haven't "really" started wedding planning, but they already have an idea of the theme for their nuptials.
"A little, you know, maybe fall, winter kind of thing and you know, we've got a lot to get done," he said.
That would put their wedding anywhere between September 23 this year and March 19, 2020.
He announced his engagement to the socialite via Instagram.
He wrote: "Sweet Katherine, so happy you said yes! I'm thrilled to be marrying you. Proud to live boldly in faith with you. Here we go!"
And he recently revealed that he wants to have 'lots of kids' with his 29-year-old fiancée.
"I always want to be that guy that works to live, not lives to work," he said.
"I think I want to spend just a lot of time at the farm and a lot of time catching a lot of fish and seeing lots of sunsets."
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