Jennifer Aniston has been seeing ''confidence counsellor'' ahead of George Clooney's wedding.

The 'Horrible Bosses' actress - who is engaged to Justin Theroux - is said to be nervous of coming face-to-face with ex-husband Brad Pitt and his fiancee Angelina Jolie when their mutual friend ties the knot with lawyer Amal Alamuddin later this year, so is doing everything she can to put her anxieties to rest.

A source said: ''Jen's no stranger to therapy, so she decided to seek some help.

''At the wedding, she'll have Justin there for support, but the thought of seeing Brad and Angelina is quite overwhelming. The therapist has been helping to build her confidence and eliminate the fear she seems to have built up about coming face-to-face with them.

''She has also been having hypnotherapy.''

Though Jennifer has seen Brad and Angelina only once, at the 2009 Oscars, since they divorced nine years ago, she is said to be particularly concerned about the wedding as it will be so intimate.

The source added to Britain's Grazia magazine: ''The Oscars were one thing, but George's wedding will involve being in a smaller, far more intimate group where they won't be able to avoid one another. Jen wants to be as breezy as possible.

''She has been doing role plays with her confidence coach and will be as prepared as she can be.''