With a government shutdown looming as federal funds are set to run out Dec. 21, some lawmakers could again promise to donate their shutdown salaries to charity rather than cash in while many federal workers go without pay.

That was the case in 2013, when some lawmakers, including Colorado’s Republican Sen. Cory Gardner, who was then a congressman, said he’d donate pay collected during the shutdown to charity.

U.S. Sen. Michael Bennet (D-CO) promised to donate his congressional shutdown pay to the Weld County Food Bank and other charities, while Democratic Congressman Jared Polis promised to return his salary to the U.S. Treasury for debt relief. U.S. Rep. Mike Coffman (R-CO) said he’d donate his salary to the Red Cross.

According to the Denver Post, Gardner said he’d give the roughly $7,700 he earned during the 16-day shutdown to charities in his district, including the Weld County Food Bank, which at the time was helping feed flood victims.

It’s not known whether Gardner did, in fact, donate his salary, as he declined to respond to the Washington Post when they asked the 237 lawmakers who made such promises for receipts.

Bennet, Coffman, and Polis, on the other hand, did respond to the Washington Post’s inquiry with proof of donation.

Some of the lawmakers who initially promised to donate ended up keeping their pay, the Washington Post found, with some arguing that they had only planned to donate if workers who served during the shutdown weren’t paid retroactively.

Gardner’s office did not return a phone call seeking to know if he plans on taking home a paycheck should another shutdown come to pass, or if he ended up donating to the Weld County Food Bank back in 2013.

The Weld County Food Bank didn’t return a request for comment.

Now, as the bitter fight over funding for a wall along the nation’s Southern border continues in Washington, it’s unclear if the White House and congressional leaders will come up with a solution to fund the government before the Dec. 21 deadline.

Last week, Trump said he’d be “proud” to shut down the government over border security, but White House press secretary Sarah Huckabee Sanders appeared to walk back that attitude in a Fox News interview this morning when she said they’d look for a solution to avoid a funding lapse.

Still, Democrats appear unlikely to budge when it comes to Trump’s demands for border wall funding.