Lawmakers are headed back to the Capitol on Oct. 2 to clean up a tax mess that a hastily passed compromise created last legislative session.

Gov. John Hickenlooper signed an executive order Thursday evening declaring the first special session for the Colorado General Assembly since 2012. It will address what he called the “unintended consequence” of Senate Bill 267, a measure that raises money for rural hospitals and transportation but inadvertently cuts off retail marijuana tax revenues for special districts, such as Denver’s Regional Transportation District.

“Since this issue was discovered, we worked with department staff, stakeholders, sponsors and members of the General Assembly on options to correct this unintended consequence,” Hickenlooper said in a statement. “After hearing about the potential impact on citizens around the state, it is clear that this problem is best solved as soon as possible. This special session will be solely to address this one narrow correction.”

The session should be quick. The original bill passed wth bipartisan support, leaving little significant opposition to making the fix.

“The bipartisan sponsors of SB267 have all agreed that the omission of special districts from the retail marijuana revenue distribution was an unintentional error,” House Speaker Crisanta Duran said in a statement. “Now that the governor has called a special session to resolve this issue, we owe it to the affected special districts and the people they serve to correct this mistake as quickly and efficiently as possible. We’ll be ready to go in October.”

Sen. Jerry Sonnenberg, R-Sterling, the Senate president pro-tem who was a prime co-sponsor of Senate Bill 267, said Thursday night had not heard from the governor’s office until after Hickenlooper announced the special session.

“This is not the way government should work in Colorado,” he said in a statement. “Calling a special session without an understanding of the game plan, or proper consultation with the legislators involved, is an irresponsible use of taxpayer dollars.”

House Minority Leader Patrick Neville, a Republican from Castle Rock, said Thursday before the announcement that the drafting error highlights what happens when a few legislators draft a major spending bill behind closed doors.

“This is an example of the kind of backroom deals that get cut without any of the other legislators’ input,” he told Colorado Politics.

Neville is advocating a separate plan for the entire $28.5 billion state budget to be taken out of the hands of the bipartisan Joint Budget Committee and be turned over to the committees of reference in each chamber to allow more input from more lawmakers.

The 2012 special session over civil unions for same-sex couples lasted three days. In 2006, the last special session before that, lawmakers met for five days before reaching a compromise over public benefits to undocumented resident with then-Gov. Bill Owens.

(Editor’s note: This story corrected to say the 2012 special session last three days, not two.)