U.S. Sen. Steve Daines, a Republican, has teamed up with Sen. Debbie Stabenow, a Michigan Democrat, to obstruct an escape clause abusing the conservation easement tax benefit.

The pair reintroduced the Charitable Conservation Easement Program Integrity Act of 2019 on Thursday. It would limit tax deductions on conservation easements to 2.5 times the owners original cost for the property.

An Internal Revenue Service report to Congress noticed that abuses of the advantage totaled $20 billion somewhere in the range of 2010 and 2016, with a few owners claiming 20 times their original purchase price on the easement deduction.

“The conservation easement tax incentive is meant to help conserve land and protect family farms, not be used as a tax shelter,” Daines wrote in an email on Thursday. “This bill makes several important changes to the tax incentive that will help curb abuses and make sure that the program remains an important conservation tool.”

The bill received support from many land trust associations, which have been worried about their conservation endeavors getting stained by abusive tax shelters. The Nature Conservancy, Land Trust Alliance, Montana Land Reliance and Ducks Unlimited were among the advocates for the bill.

“From a Montana and national private land conservation perspective, this legislation is key to stopping abusive syndicated transactions while ensuring that tax incentives for land conservation remain available for landowners to help conserve open lands, family farms and ranches, wildlife habitat and so much more,” Montana Association of Land Trusts director Glenn Marx said in an email statement.

Conservation easements allow a property owner to sell development rights to the federal government for all or part of land that has value for traditional agriculture, wildlife habitat or recreational opportunities. The bill’s value cap would not apply to family-owned partnerships.