An anti-fracking US politician accidentally voted the wrong way in a debate on the issue making the mining operation legal in her home state.
North Carolina state representative Becky Carney said she voted mistakenly to override a veto by the governor of a bill to allow the shale gas exploration.
When she realised the mistake she was told she could not change it because that would have altered the outcome.
Ms Carney said she pushed the green "yes" button to override Democratic governor Beverly Perdue's veto of the measure before realising she wanted to vote red, or "no."
Her "yes" vote made the tally 72-47 - just above the 60% required to override a measure in the Republican-controlled state legislature. The chamber's rules prevent members from changing a vote if it affects the outcome.
Ms Carney had voted earlier against fracking. She said she feels terrible about her error but acknowledged the bill passed legally.