Jennifer Aniston's secret wedding officiated by Jimmy Kimmel

Justin Theroux, left, and Jennifer Aniston arrive at the 2015 Vanity Fair Oscar Party on Sunday, Feb. 22, 2015, in Beverly Hills, Calif. (Evan Agostini / Invision)

NEW YORK -- Howard Stern has revealed details about the secret wedding between Jennifer Aniston and Justin Theroux, including that Jimmy Kimmel officiated.

Stern was a guest at the Los Angeles ceremony last Wednesday that Aniston and Theroux disguised as a birthday bash for Theroux. Stern said on his radio show Monday that he knew beforehand that it was a wedding because the couple asked him to give a speech.

But Stern said the affair was extremely secretive and that guests had to hand over their phones. He said Kimmel did "a beautiful job" officiating, and that Sia performed.

Other guests, he said, included Ellen DeGeneres, Whitney Cummings and Orlando Bloom.

The marriage is the second for 46-year-old Aniston, who got divorced from Brad Pitt in 2005, and the first for 44-year-old Theroux.