The 86-year-old Playboy founder and editor-in-chief and the 26-year-old Playmate signed an "ironclad" prenup in preparation of their New Year's Eve wedding, Us Weekly reported in its latest issue.
According to an Us source, Harris, who previously starred in The Girls Next Door, will not be added to Hefner's will that covers his estimated $43 million fortune although they're married now.
Hefner's money is reportedly still promised to "his children, the University of Southern California film school and a variety of charities," said the source, suggesting that Harris therefore must've wed for the right reasons.
Hefner and Harris -- who was December 2009's Playboy Playmate -- got engaged over the holidays in December 2010 but Harris called off the wedding in June 2011 just days before she was set to walk down the aisle. TMZ recently reported that Harris had left Hefner at the time because she needed a break from their relationship to gain some independence before settling down.
Harris reportedly moved back into the Playboy mansion earlier this year, and once reunited, the couple worked things out and eventually came to the conclusion they should get engaged again and tie the knot. News of their second engagement first surfaced in early December.