Coca-Cola on Tuesday became one of a small but growing number of companies offering paid leave for new fathers as well as mothers — a step advocates say brings modernity to benefits packages stuck in the “Mad Men” era.

The Atlanta beverage giant said beginning next year it will offer six weeks paid leave to all U.S. employees of either sex who have new children, including adoptive parents and those planning to be foster parents.

Coke said one motivation is to help it recruit and retain millennials.

Calls for unisex paid leave benefits have been increasing in the United States, where policies have been slower to change than in other nations where time off for all parents is standard.

At present, U.S. companies with more than 50 employees are only required to offer expecting mothers 12 weeks of unpaid leave, although many corporations go beyond that with some level of paid time off.

Fathers are generally not included in those plans, though a number of tech companies have added them as recruitment tools.

But many American workers — especially men — don’t take the leave even when offered because they fear it can sidetrack career paths or that they will be seen as unambitious, according to studies.

“What we have are these old stereotypes around which (parental leave) policies were designed,” said Josh Levs, author of a book on fatherhood and paid leave, “All In.” Three years ago, while working at CNN, Levs fought his own leave battle against parent Time Warner. The company settled the complaint with the Equal Employment Opportunity Commission in late 2015, opening parental leave to fathers.

“This hurts women and men,” Levs said of single-sex leave policies.

Cost can be a factor. The University System of Georgia turned down a 2014 proposal that would have provided eight weeks of paid leave for both mothers and fathers after the birth or adoption of a baby. The system rejected the proposal, presented by faculty at the University of Georgia, saying it would be too expensive.

Coke said Monday its younger employees championed the idea as a smart strategy, particularly for attracting talented people their age. Coke estimates that millennials, ages 18 to 34, will make up more than half its global workforce by 2020.

The added benefits will supplement the six-to-eight weeks of paid leave Coke already provides to birth mothers through short-term disability, the company said.

A few well-known companies, including Facebook, Apple and Google, already use generous parental leave benefits for both men and women — some as much as three or four months — to lure workers and make jobs more attractive.

Streaming giant Netflix and online arts and crafts marketplace Etsy recently created parental leave policies on steroids, offering moms and dads one-year and six-month leaves respectively.

Business is not alone in beefing up the leave policies. The city of Atlanta last year began offering paid parental leave of six weeks for all city employees, no matter the gender, who are primary caregivers while non-caregiver were offered two weeks of paid time.

“The adoption of paid family leave will provide much needed financial support to our employees and their families,” Mayor Kasim Reed said at the time of the announcement.

Kelly Cahill Timmons, an associate dean at the Georgia State University’s College of Law, said Coke’s plan could influence other old-line corporations, demonstrating that such moves are not limited to the tech sector. Bank of America, Johnson & Johnson and Goldman Sachs have also extended unisex paid parental benefits.

She praised Facebook CEO Mark Zuckerberg’s decision to took paternity leave for the birth of his daughter.

“The biggest test,” she said, “is going to be who is going to take it.”