Brad Pitt and Angelina Jolie decided to get married because of her work with the United Nations.
Apparently the couple feared she may not survive a dangerous new mission with the UN helping to battle drug lords.
The mother of six adopted and biological children, who is a goodwill ambassador for the UNHCR refugee organisation, will be involved when the UN launches a fresh war on South American crime bosses.
A source told The Sun: "Brad's terrified something bad will happen to her. It's why he wanted to cement things with a wedding."
Earlier this year Angelina wrote a farewell letter to her fiancé Brad after becoming scared for her life on a UN mission.
She said: "I wrote a note to Brad and figured if anything happens he'll find it.
"They gave me a briefing and they said everybody needs to write down their blood type."
The couple - who met on the set of 'Mr and Mrs Smith' in 2005 - have kids Knox, Vivienne, Pax, Shiloh, Zahara and Maddox together.
They announced their plans for a wedding last month.