They approved a newly revised plan that eliminates the constitutional ban on civil unions.
In order for the amendment to be put on the November ballot, both the House and Senate had to pass the same legislation that was passed a few years ago without any new changes.
Dozens were at the Statehouse today anticipating action from the Senate including the group Freedom Indiana, who oppose the amendment.
The Senate will be back in session on Monday. The House voted in favor of the bill last month.