Nicole Kidman revealed to W Magazine how a feature in her bathroom has kept her marriage with Keith Urban, both 57, strong almost two decades on from when they tied the knot in Sydney, Australia.

Nicole Kidman and Keith Urban are both masters of their craft — her at acting and him at singing. And having been married for 19 years, the two have figured out how to make things work. In an interview with W Magazine published on Friday, January 3, Kidman, 57, shared the secret that has allowed her marriage to Urban, also 57, thrive.

The Golden Globe winner married the country singer in June 2006. The couple are the parents of daughters Sunday, 16, and Faith, 13.