Anyone who is appointed to Donald Trump’s administration will be banned from becoming a paid lobbyist for five years after leaving the White House, his transition office announced Wednesday night.

Trump aide Sean Spicer laid out the lobbying ban during a hastily arranged conference call with reporters, the Trump team’s first since last week’s election. All appointees will be required to sign a form agreeing to abide by the ban before starting work.

Throughout the campaign, the president-elect vowed to “drain the swamp” of Washington, partly by decreasing the role of lobbyists and special interests in policymaking. Spicer said this is the first step toward that goal.

The Obama administration has its own ban in place. Anyone who had been a registered lobbyist in the prior two years is prohibited from joining — unless they get a waiver. Former Obama administration officials have also been banned from lobbying the White House.

Separately, transition officials said Trump will meet with Nikki Haley, South Carolina’s GOP governor, on Thursday, fueling speculation she’s being eyed for secretary of State.