Columbia University no longer directly invests in oil and gas companies and doesn’t plan to do so, the university announced Friday.

“The university does not hold any direct investments in publicly traded oil and gas companies, and is formalizing this policy of non-investment for the foreseeable future,” the university said in a statement.

But Columbia reserved the right to reverse its policy should oil and gas companies revise their business models in the future.

“Recognizing that certain oil and gas companies aim to transition their businesses to net zero emissions by 2050, the University may make an exception to its non-investment policy when a credible plan exists for a company to do so,” the statement said.

In 2017, Columbia cut its ties to thermal coal companies. In the years before and since, students have called for the university to go a step further and divest completely from fossil fuels.