New Delhi, Jan 17 : John Mayer is planning to ask Jennifer Aniston to marry him when she turns 40 on February 11, according to reports.

The ''Gravity'' singer has even invested in a custom made engagement ring for her, reports the China Daily.

A source told America''s Star magazine: "Money''s no object for John. He didn''t want to buy something that anyone else had, so he sketched it and is having it custom-made."

Apparently, John is determined to make the proposal as special as possible and has previously said he would find a "creative" way to pop the question.

He said: "I think I''d be pretty good at proposing. I''d figure that out. I''d get creative."

It was recently reported Jennifer is keen tie the knot as soon as possible, and has her heart set on a lavish Greek wedding.

A source said: "John''s finally agreed to marry her - and they''re now planning a traditional Greek Orthodox wedding." (ANI)