With the Internal Revenue Service reweighing its rules for what should legally count as property for real estate investment trusts, attorneys are bracing for stricter asset class definitions and a slowdown to the recent REIT application boom, Law360 reports.

Specifically, the IRS is looking into whether its “real estate” definitions for REITs should be changed or refined in any manner, according to three filings last week with the U.S. Securities and Exchange Commission made by companies in the midst of seeking conversion approvals.