The Department of Labor has proposed a rule regarding how plan sponsors and fiduciaries can include alternative assets in 401(k) retirement accounts.

The proposal is in response to President Donald Trump’s executive order, released in August, which directed the Labor Department and the Securities and Exchange Commission to facilitate expanded access to alternative assets in 401(k)s. Alternative investments are a broad category that includes real estate, cryptocurrencies and private-market assets, among others.

“This proposed rule will show how plans can consider products that better reflect the investment landscape as it exists today,” Labor Secretary Lori Chavez-DeRemer said in a statement.

Although 401(k) plans are already not prohibited from including such assets, fears of lawsuits challenging their investment decisions have kept most plan sponsors on the sidelines.

The Labor Department rule creates a so-called “safe harbor” that can help shield plan sponsors from litigation. It identifies six factors for a plan fiduciary to “objectively, thoroughly, and analytically consider” when selecting alternative investments. The six factors are performance, fees, liquidity, valuation, performance benchmarks and complexity.