JEFFERSON CITY, Mo. (AP) – Missouri’s House budget leader says lawmakers might not have changed corporate tax law if they’d known what it would actually cost.

Republican House Budget Committee Chairman Scott Fitzpatrick told The Associated Press that lawmakers had poor information when the 2015 bill came up for a vote. The measure was estimated to cost about $15 million annually. Corporate tax revenues dropped more than $155 million the first fiscal year it was implemented, though it’s not clear whether that was all from the tax change.

Democratic Auditor Nicole Galloway says that’s not acceptable. She’s auditing corporate income tax law as part of a review of policies that have contributed to budget crunches.

It’s unclear whether lawmakers can undo their action. Fitzpatrick says a repeal could be interpreted as an unconstitutional tax hike.