Kate Hudson and Owen Wilson are planning to marry in June.
The couple - who have had an on/off relationship since 2006 - decided they were ready to commit after enjoying a romantic holiday together in France in February.
A source said: "They realised how devoted they are to each other. They don't want to ever be apart again "Kate and Owen don't feel the need for flashy engagement rings, they're planning to tie the knot in June."
The couple are said to be torn between having their wedding at Kate's mother Goldie Hawn's house in Aspen or Owen's home in Hawaii. They have decided to keep the ceremony small, and Kate - who has a five-year-old son Ryder with her ex-husband Chris Robinson - is shopping for a wedding dress.
A source added to the National Enquirer magazine: "She looked at some designers when she and Owen were in Paris.
She's really into Dior but hasn't chosen anything yet. She'll probably wear something simple and flowing. "Owen and Ryder have bonded so well since he and Kate first started dating. Owen already thinks of Ryder as his son. Owen is ready to have kids of his own with Kate, his biological clock is ticking."
(China Daily/Agencies, April 3, 2009)