The Department of Homeland Security said Wednesday it intends to publish a proposed rule that would limit the length of time foreign students are allowed to stay in the United States.

Since 1978, foreign students, or F visa holders, could stay in the U.S. for their “duration of status,” meaning as long as they were enrolled as a full-time student. The proposed rule set to publish Thursday would allow for foreign students and exchange visitors to stay up to the duration of the program they are participating in, not to exceed a 4-year period.

DHS officials said the rule is to correct a system in which foreign students have “taken advantage of U.S. generosity” by becoming “forever students.”

“For too long, past Administrations have allowed foreign students and other visa holders to remain in the U.S. virtually indefinitely, posing safety risks, costing untold amounts of taxpayer dollars, and disadvantaging U.S. citizens,” a DHS spokesperson said in a statement. “This new proposed rule would end that abuse once and for all by limiting the amount of time certain visa holders are allowed to remain in the U.S., easing the burden on the federal government to properly oversee foreign students and history.”

If finalized, the rule would require foreign students to be regularly assessed by DHS to remain in the U.S. for a longer period.

Advocates who represent foreign students, said this rule will create uncertainty for these students and leave them with more bureaucratic hurdles to clear.

“International students deserve assurance that their admission period to the U.S. will conform to the requirements of their academic programs,” said Miriam Feldblum, president and CEO of the Presidents’ Alliance, which represents 500 presidents and chancellors of public and private colleges and universities. “They already represent the most closely monitored population in the U.S. and are subject to rigorous oversight by DHS and academic institutions.”

The proposed rule could dissuade some students from choosing to study in the U.S., said Fanta Aw, executive director and CEO of NAFSA: Association of International Educators.

“It will certainly act as an additional deterrent to international students choosing to study in the United States, to the detriment of American economies, innovation, and global competitiveness,” Aw said in a statement.

The logistical hurdles, such as pauses in visa interviews, have already caused international student enrollment to take a hit. A report from the Institute of International Education, which collected feedback from hundreds of U.S. higher education institutions, found that 35 percent of the schools they surveyed saw a decrease in applications for this fall, compared with only a 17 percent decrease the previous academic year.

There are also serious financial implications for colleges if fewer foreign students enroll, because they typically pay more tuition and receive less scholarship support.