Minnesota is poised to raise the legal marriage age to 18 in all circumstances, a move that could make the state the third in the nation to fully ban child marriage.

The ban on underage unions was approved unanimously by the state Senate Wednesday, sending the measure to Gov. Tim Walz, who is expected to sign it.

Under current law, 16- and 17-year-olds can obtain a marriage license with permission from a legal parent or guardian and a judge. The new measure removes that option, prohibiting the state from approving or recognizing legal unions involving Minnesota minors.

The Minnesota House approved the measure unanimously last year.

Supporters point to research showing that teens in the U.S. who marry before 18 complete less education and face higher rates of poverty, mental health and drug problems later in life. They say underage girls are often coerced or forced into legal unions they cannot easily escape.

“Marriage, even at 16 or 17, has devastating lifelong repercussions,” Fraidy Reiss, an activist working to stop child marriage across the country, said at the State Capitol earlier this year. “It destroys a girl’s health, her education, economic opportunities.”

Global and domestic efforts to end child marriage have picked up steam in recent years. The United Nations is working to end the practice worldwide by 2030, calling it a violation of rights of women and girls. A number of states have moved to raise the minimum age or set additional requirements for granting underage marriage licenses. Just two other states, Delaware and New Jersey, have adopted full bans. Legislators in Pennsylvania recently approved a ban of their own with unanimous support. The legislation is awaiting the signature of the state’s governor, who said he supports the change.

While the DFL-led House passed the Minnesota ban last year, it stalled without a hearing in the GOP-controlled Senate. Republican Sen. Warren Limmer, chairman of the Senate’s judiciary committee, said earlier this year that lobbying from advocates convinced him to change his mind and support the measure. The Maple Grove Republican said he was concerned about stories of young women forced into marriages with older men.

“It’s almost like buying a bride. And that should never happen in our state,” he said in February. “After considering the legal principles versus the intention of the bill, I’m becoming sold on the idea that it’s a proper thing to do.”

Walz has said he supports the effort, while noting the state should consider and respect cultural traditions in certain communities.

Sen. Sandy Pappas, a St. Paul Democrat sponsoring the legislation, said Wednesday that the bill does not void existing legal unions. She said marriages between couples who wed before they moved to Minnesota will also be recognized, even if one or both people were under 18 at the time, but those involving current residents who travel to other states to marry as minors for the purpose of getting around the state ban will not.

It’s not clear how common child marriages are in Minnesota. About 2,000 Minnesotans ages 15 to 19, less than 1% of the population, had been married in 2014, according to census data.