Their action comes one day after the proposal was killed by one vote.
Senator Tony Grindberg's amendment only provides funds for the buyout and does not force the board to fire Shirvani.
Grindberg says Senators started to rethink their vote and pushed for it to be reconsidered.
The Board of Higher Education backs Shirvani, however the North Dakota Student Association expressed a vote of "no confidence" this weekend.
The buyout amendment passed by a vote of 28-19.
(Sen. Tony Grindberg / (R) Fargo) "Folks that changed their position on the vote, this reinforces the message that current direction and concerns are broad based. Whether it's the legislature or the students There are a number of folks who are expressing their concerns and the legislature spoke."
Shirvani has been in charge of the University System since last July.
His contract runs through June 2015.
If the board chooses not to get rid of Shirvani before his contract is up, the $850,000 will go back to the general fund.
The buyout is included in the University System Budget that moves to the House for it's approval.