Victory Fund, a political organization that backs LGBT candidates for office, is planning to endorse a presidential candidate for the first time in its history.

Pete Buttigieg, the openly gay mayor of South Bend, Indiana, is set to formally receive the group’s backing June 20 in Boston, according to an email obtained by BuzzFeed News. Annise Parker, the former mayor of Houston who is now Victory Fund’s president, is expected to join the event.

“This truly is a historic first for our work, and our community,” the email says.

The move had been expected since Buttigieg began rising as a contender in the Democratic field — the group has historically only endorsed LGBT candidates. But Victory Fund board members were notified of the official plans Wednesday. Early endorsements from large outside groups, which have been rare in a tightly contested field of nearly two dozen Democrats, can be major boosts to campaigns.

The endorsement is a sign of how Buttigieg’s candidacy has animated the LGBT community. Buttigieg and his husband, Chasten, have been featured on the cover of Time magazine, and he has spoken out about Vice President Mike Pence’s anti-LGBT agenda while Pence served as governor of Indiana.

In a statement to BuzzFeed News, the Victory Fund said it had not yet made any formal announcements, but hinted one was likely to come soon. “Although we have never endorsed at the presidential level … perhaps that will change soon. But no announcement from us just yet,” said Elliot Imse, a Victory Fund spokesperson.

“Mayor Pete’s candidacy is a historic moment for our community and a milestone in American politics — and he’s inspiring voters across the nation.”

Buttigieg gave a deeply personal speech at a Victory Fund brunch in April, where he spoke of his own experience coming out.

“If you had offered me a pill to make me straight, I would have swallowed it before you had time to give me a sip of water,” Buttigieg told the crowd. “That’s a hard thing to think about now.”

The Victory Fund’s endorsement will add to Buttigieg’s already strong fundraising muscle, according to a person familiar with the group’s endorsement process.

A spokesperson for Buttigieg’s campaign did not immediately return a request for comment.