U.S. Secretary of State Hillary Clinton will throw a wedding engagement party for U.S. Sen. Susan Collins, R-Maine.

Clinton’s plan to host the get-together was first reported by BuzzFeed. Kevin Kelly, Collins’ spokesman, said the report was accurate.

The site reported that guests include other women senators and former U.S. Supreme Court Justice Sandra Day O’Connor.

Collins announced in February that she was marrying Thomas Daffron. Daffron and Collins met when both served as Senate staffers. The couple is expected to be married during a private ceremony this summer.

Collins and Clinton served together in the U.S. Senate between 2001 and 2008, when Clitnon was a Democratic senator from New York. Both served on the Senate Armed Services Committee.

Collins was also highly supportive of Clinton’s 2009 nomination to become secretary of state.