Krall and Costello
Ronald Asadorian/Splash News
Diana Krall and husband Elvis Costello announced Sunday that they are expecting a baby due in December – just in time to mark the couple's third wedding anniversary.
A spokesman confirmed the pregnancy, reports the Associated Press.
The London-born Costello, 51, whose songs include "Veronica," "Pump It Up" and "Alison," currently is touring with Allen Toussaint in support of their album, The River in Reverse.
Krall, 41, is scheduled to release her new album in September.
Shortly after their marriage, Krall – saying, "I'm thankful I met the man of my dreams" – told PEOPLE of the fame factor that also accompanied being married to Costello: " I get better service at the shoe department at Barneys when I'm with him than when I'm by myself. … So I take him with me wherever I go."