They’ve worked hard for the money.

Women now make up 20% of the people who have $1 million or more saved for retirement, according to research on 15 million 401(k) accounts from Fidelity investments. That’s up from fewer than 10% in 2005.

“Part of it is that we’ve seen more women actively participating in 401(k) plans and contributing more,” said Jeanette Thompson, senior vice president at Fidelity Investments, according to a report from the New York Times. And, despite the well-documented wage gap between men and women, “women are saving more,” Thompson added.

Self-made female millionaires say that the climb to surpass the $1 million threshold has required diligence and sacrifices to achieve, but that the feeling of making it as a full-fledged millionaire makes up for any austerity they exerted along the way.

Melanie Bajrovic, 32, became a millionaire at 27 by investing in commercial and residential real estate properties.

“I started working when I was really young,” she told Moneyish, recalling how helping out in her parents’ bar and restaurant, opened after they settled in Canada from the former Yugoslavia, imbued her with a strong work ethic.

When she was 22, having having held positions in real estate and marketing through her undergraduate years, she had saved enough money (about $20,000, she estimates), to buy a small home. And so began her journey in real estate, which, by now, “has almost doubled [her] net worth.”

For Bajrovic, becoming a millionaire meant personal sacrifices, like hanging back when her friends would overspend on recreation during her 20s. “Sure, I felt sorry for myself when all my classmates were out partying,” but living “as [frugally] as I could, only buying the things I needed, working every holiday [and] every weekend,” helped her realize her dream.

What’s more, Bajrovic shuns impulsive luxury expenses altogether, preferring to splurge on indulgent vacations, instead. Consumers “spend too much on things,” she admonished. “Materialistic things, status symbols, handbags [like] Louis Vuitton’s, Prada’s, Christian Louboutin’s. I’m wealthy, [but] I don’t own a Louis Vuitton bag. I don’t even pretend to.”

“You can’t overconsume to portray a high status lifestyle and become wealthier, become a multimillionaire, all in the same lifetime,” by exerting poor spending discretion, she asserted.

For entertainment industry executive Jacquie Jordan, a former television showrunner turned founder of marketing company TVGuestpert, those sacrifices hit an even more personal level.

“I ended up not having children,” because “I was very aware that if I couldn’t do it financially well, I didn’t want to,” Jordan confessed to Moneyish. Indeed, though having children has many benefits beyond the financial, it can easily cost more than $1 million to raise a single child.

Also read: The shocking cost to raise a child in America today

Jordan says other spending decisions, like avoiding using credit and only spending money she’s already earned, have also helped her make her goal happen.

Certified financial planner David Rae believes that the biggest mistake both men and women make that holds them back from become millionaires is overspending.

“I think right now rent or mortgages, housing is really expensive in most major cities,” he said, recommending that young people spend no more than 30% of their income on such an expense. But, on a day to day basis, Rae says saving money is not quite as hard as it seems for many Americans.

Small things like eating out, or going for manicure/pedicures or regular hair appointments can chip away at your bottom line, as can leaving money in liquidity and ignoring the benefits of investing.

“Women are better at saving a larger amount of their income, but men are generally more aggressive investors. Step one is to save the money,” Rae said, concluding that investing is the secret to making money multiply. “Step two is to make the money grow.”