Olivia Wilde has called fiancé Jason Sudeikis “smart” for picking out the perfect engagement ring.

The 28-year-old actress announced her engagement to the 37-year-old Saturday Night Live star back in January.

Speaking to Extra, she admitted she was thrilled at her partner’s choice of an antique round cut diamond sparkler.

“Smart boys listen,” she declared. “Smart boys are attentive and intuitive. He may have spoken to some of my friends.

“Everybody kept it a secret from me. But I’m glad I was totally shocked. I had no idea.”

The star, who is busy promoting her new comedy The Incredible Burt Wonderstone, also put her slim and trim appearance down to being “in love.”

Olivia plays a stagehand who wants to be a magician in the feature which also stars Steve Carrell and Jim Carrey.

“I’ve always loved magic,” she told Extra.  “I was the kid who had a magician at every birthday party.

“I had the magic kit but I was never very good with it. Slight at hand I’m terrible at, but I do love it. This film renewed my love for magic in a way.”

Olivia and Jason started dating in November 2011 and live together in New York City.

It will be the second marriage for both stars.

Olivia divorced Italian filmmaker Tao Ruspoli back in 2011 after eight years of marriage.

Jason split from writer Kay Cannon in 2010 after six years of marriage.