U.S. Rep. Bruce Poliquin agreed on Monday to pay back nearly $500 after his office admitted a January “bookkeeping error” that billed taxpayers for two nights in a D.C. hotel.

But it’s not likely to happen again, since the congressman’s sleeping arrangement has changed: Since March, the Republican from Maine’s 2nd District has been sleeping in a Murphy wall bed that he bought with his own money and had installed in his office.

The error was flagged on Friday by the Kennebec Journal after it showed up in disbursements for the first three months of 2015, which were recently released for all members of the House of Representatives. Under House rules, travel expenses such as gas are reimbursable, but housing, meals and other expenses at the member’s residence or in Washington are not.

By Monday, Poliquin, a Republican from Maine’s 2nd District, agreed to pay $495.49 — $50 more than the cost of a room for two nights — with a personal check payable to the U.S. Treasury, according to a letter sent by Julie Mulvee, his deputy chief of staff, to the chairwoman of the Committee on House Administration.

“Congressman Poliquin is insistent that hard-working American taxpayers not be subjected to further national debt from this bookkeeping error,” Mulvee wrote.

In the letter, Mulvee said until the Murphy bed was installed on March 16, Poliquin stayed at area hotels for 28 different nights. She said she “inadvertently entered” costs for two of those nights into the bookkeeping system and the office has “put in place new procedures to help ensure future bookkeeping errors do not occur.”

It’s not uncommon for members of Congress to sleep in their offices. The New York Times highlighted some who did it in 2011 and Citizens for Responsibility and Ethics in Washington, a watchdog group, criticized members who they said were doing it in 2011, saying, “If members didn’t want to find housing in Washington, they shouldn’t have run for Congress in the first place.”

The Murphy bed has long been in Poliquin’s plans. He told WCSH in December that he’d be getting one.

“He loves it,” said spokesman Michael Byerly.

And now, taxpayers can also rest easier.