(Reuters) - The Boy Scouts of America said on Monday the group would begin accepting transgender boys, bucking its more than a century-old practice of using the gender stated on a birth certificate to determine eligibility.

“Starting today, we will accept and register youth in the Cub and Boy Scout programs based on the gender identity indicated on the application,” Boy Scouts of America communications director Effie Delimarkos said in an emailed statement.

Delimarkos cited shifting definitions of gender under state laws, which can “vary widely from state to state,” in explaining the change.

She said that while the organization offers programs for all youths, its Cub and Boy Scout programs are specifically for boys. The change will allow children to apply even if male is not listed on their birth certificate.

Advocacy group Scouts for Equality applauded the move: “This is another historic day for the Boy Scouts of America. The decision to allow transgender boys to participate in the Cub Scouts and the Boy Scouts is an important step forward for this American institution.”

In 2013, the Boy Scouts voted to lift a ban on openly gay scouts that had been in place throughout the organization’s history after gay rights advocates gathered petitions with more than 1.8 million signatures in support of ending the ban.

Support also came from some of the biggest American churches, including the Mormons and the Methodists, two of the largest scouting sponsors in the United States.

Two years later, the organization lifted its blanket ban on gay adult leaders after its president, former U.S. Defense Secretary Robert Gates, called the ban “unsustainable” in the face of numerous lawsuits challenging the policy on grounds of discrimination.

The Boy Scouts of America, whose stated mission is to prepare youth for life and leadership, has nearly 2.3 million members between the ages of 7 and 21 and roughly 960,000 volunteers in local councils throughout the country, according to its website.