By a vote of 21-16, the senators approved the law despite an important religious opposition.
During the weekend, the Governor Lincoln Chafee signed it. He is actually a supporter of marriage equality and said in a statement following the signature allowing the civil unions:
"This extraordinary exemption eviscerates the important rights that enacting a civil union law was meant to guarantee for same-sex couples in the first place," he said.
But he added that the law "provides a foundation from which we will continue to fight for full marriage equality," as an associated press reports.