Hundreds of people each year are telling the IRS they deserve a reduced tax bill because they are owed reparations for slavery, and a new government watchdog report indicates the IRS might be paying out some of those claims.

The Treasury Inspector General for Tax Administration released a report Wednesday that said the Internal Revenue Service needs to do a better job spotting “frivolous” tax arguments. TIGTA said more than 220,000 potentially frivolous tax returns were filed in fiscal year 2014 and were not detected by the IRS.