Washington State voters have approved Referendum 71, a ballot measure to uphold the law granting expanded domestic-partnership rights to same-sex couples.

Referendum 71 passed into the win column on Thursday, according to the Associated Press. 

“With about 72 percent of the expected vote counted Thursday in unofficial returns, R-71 was leading 52 percent to 48 percent,” the AP reported.

The vote makes history, according to the AP.

“National gay-rights groups say the passage of Referendum 71 marks the first time a state's voters have approved a gay equality measure at the ballot box,” the AP reported.