UPDATED 12:45 P.M.: AUGUSTA — Sen. Susan Collins has become just the third U.S. senator ever to cast 6,000 consecutive votes.

The Maine Republican hasn’t missed a roll call vote since taking office in 1997, and she reached the 6,000-vote milestone Thursday on two votes related to the Iran nuclear deal.

She voted Yea on a motion to invoke cloture on the S.Amdt. 2656 to S.Amdt. 2640 to H.J.Res. 61 (Hire More Heroes Act of 2015). The amendment reads, “To prohibit the President from waiving, suspending, reducing, providing relief from, or otherwise limiting the application of sanctions pursuant to an agreement related to the nuclear program of Iran.”

It got 53 Yeas and 45 Nays.

She says the feat shows constituents that she’s committed to her job.

Republican Chuck Grassley of Iowa has an even longer voting streak, with more than 7,400 votes dating to 1993.

The late Sen. William Proxmire is in the No. 1 spot. The Wisconsin Democrat cast 10,252 consecutive votes from 1966 to 1988.

UPDATED 7:11 A.M.: AUGUSTA — No one knows better than Maine Sen. Susan Collins how difficult it can be to go more than 18 years without missing a single vote in Washington — except, perhaps, her staff.

When the Republican travels home for the weekend, they’re in charge of closely watching airlines to ensure her plane is on time and hasn’t been canceled. And during Maine’s brutal, snowy winters, that can be a herculean task.

“It probably puts some stress on my staff,” Collins said with a laugh.

At least, it seems to have paid off.

Collins is to become just the third U.S. senator to ever cast 6,000 consecutive votes. It’s a feat she believes shows her constituents that she’s committed to her job, which she says is particularly important at a time when the public’s opinion of government is so low.

“This is the way that I can help assure the people that I’m privileged to represent that I’m doing everything I can to make sure their voices are heard,” said Collins.

Her record stood at 5,998 votes as senators prepared for possible votes Thursday on measures related to the Iran nuclear deal.

Keeping the streak alive hasn’t always been easy.

She once twisted her ankle while racing into the Senate before managing to vote just as the as the gavel was coming down. Another time, she was already at the airport and had to rush back to the Capitol when a last-minute vote had been called.

Collins’ perfect attendance speaks to the qualities that voters like about her: she’s hardworking, determined and steadfast, said Mark Brewer, a University of Maine political science professor. She probably knows that her opponents will try to use it against her if she misses a vote because of something preventable, he said.

“She has played it up so much and put so much importance and emphasis on it that if it were to end for a reason that could have been avoided, then I think it could be used against her in the next campaign,” Brewer said.

While Collins is the longest sitting senator to never have missed a vote, Republican Chuck Grassley of Iowa has a longer voting streak. He hasn’t missed a vote since 1993 and cast his 7,442th consecutive vote in August.

And Collins has quite a bit of work if she wants to knock former Sen. William Proxmire from the No. 1 spot. The Wisconsin Democrat cast 10,252 consecutive votes between 1966 and 1988.

“That’s a record that I think will endure the test of time,” Collins said.