With millennials and Gen Z entering into parenthood, genderless clothing for babies and kids under the age of 12 is on the rise.

“More childrenswear brands are targeting millennial parents, as the generation now accounts for the majority of new parents,” said Ayako Homma, consultant at Euromonitor International. “Millennial parents appear to be more open-minded when it comes to gender and prefer to give their children more clothing options in different colors and styles, without being constrained by their gender.”

That push for inclusivity among adults and kids was a big reason why Diapers.com employees Christina Carbonell and Galyn Bernard founded gender-neutral kids brand Primary in 2015. Part of their inspiration came from their time at Diapers.com, learning about reinventing the customer experience for parents shopping for replenishment items like diapers, wipes and formula. The other part came from walking around retail floors on the hunt for their own kids, finding girls clothing departments filled with pink dresses and princesses, and boys departments filled with blues and fire trucks. For Bernard, a mom of two daughters who aren’t fond of pink and purple, that meant trips to the boys department for new clothes.

“We were longing for a different brand in the market that felt more like brands we loved in the market when we were growing up, like Benetton. We wanted simplicity and colors without logos,  slogans and sequins,” she said. “Everything today is so prescriptive. We wanted to offer a place where there’s a rainbow of colors for every kid, and the pieces are super soft and comfortable.”

The brand launched by promoting a line of basics for kids, all under $25. Five years in, it’s continuing to expand its gender-neutral assortment. In 2018, Primary brought in $30 million in revenue, over two times what it saw in 2017. The brand uses its Instagram page, where it has 66,400 followers, to showcase all of its styles and colors, modeled on both boys and girls. Primary also encourages customers to post photos of their kids wearing Primary and to tag them with “#yesprimary” for a chance to be featured on the brand’s page or in future marketing efforts.

So far this year, the brand has been racking up major waitlists for new items. Around Valentine’s Day, there was a 6,000-plus waitlist for Primary’s rainbow heart pajamas, and this spring, it saw a 4,000-plus waitlist for its raincoat.

Genderless clothing for adults is fairly mainstream at this point, with brands from Gucci to Zara launching genderless lines as early as 2016. When it comes to kids clothing, more brands are going there. In October, contemporary fashion brand Cos launched a line of kids clothing for the first time, which came with a collection of genderless baby clothing. In November, children’s retailer Nununu partnered with Céline Dion to create a gender-neutral line.

In February, market intelligence agency Mintel projected the children’s clothing market in the U.S. will reach $40.6 billion by 2023. While Mintel doesn’t track gender-neutral kids clothing specifically, DeSalva said 27% of parents shop brands based on which align with their values. Because more and more millennials and Gen Zers are shifting into parenthood — the oldest members of Gen Z are 24 — she said it makes sense that this number will increase.

“These generations are more tuned into values like inclusion,” said Alexis DeSalva, senior research analyst, retail and e-commerce at Mintel.

Bernard said she thinks a big part of Primary’s success in the gender-neutral space comes from the fact that it’s been selling customers on genderless clothes since launch.

“Customers are smart, and they can tell when a brand all of a sudden makes a big, splashy launch around, ‘Look at our new gender neutral line!’ It doesn’t feel true or core to what a lot of these brands are offering,” she said. “Being a small, nimble company founded by moms, we are looking for those key insights that will make our customers’ lives easier. It’s a massive differentiator for us.”