BUCHAREST, Romania (AP) — Romanians are voting for a second day on a constitutional amendment that would make it harder to legalize same-sex marriage.

The Central Electoral Bureau said 5.72 percent of voters had cast a ballot Saturday in the two-day referendum. The vote requires a 30 percent turnout to be valid.

The conservative Coalition for Family initiated the referendum, backed by the influential Romanian Orthodox Church. During Sunday services, priests are expected to encourage the faithful to vote.

The proposed amendment would change the definition of family in Romania's Constitution to make marriage a union between a man and a woman instead of between "spouses." Same-sex marriage is already illegal in Romania.

Opponents say the new constitutional language could make LGBT people feel more like second-class citizens and could discriminate against non-traditional families.