Legislation introduced in the Senate Thursday would make it significantly harder for the Internal Revenue Service to unfairly target conservative nonprofit groups for auditing.

The Biased IRS Audit Systems Prevention Act, introduced by Sen. Richard Burr, R-N.C., would force the IRS to start providing documented justification to those selected for auditing. “When taxpayers are audited by the IRS, they deserve to know why,” Burr said, citing recent inspector general reports that found the agency may still be targeting conservative groups.