WASHINGTON – President Obama was re-administered the oath of office on Wednesday evening by Chief Justice John G. Roberts Jr., one day after the two men stumbled over each other’s words during the inauguration.

The president and the chief justice stood in the Map Room of the White House at 7:35 p.m. as they took a second run at the constitutional oath. A handful of advisers watched the proceeding, which lasted about 25 seconds.

“Are you ready to take the oath?” Mr. Roberts said.

“I am,” Mr. Obama replied. “And we’re going to do it very slowly.”

Gregory Craig, the White House counsel, said he believes the oath was “administered effectively and that the president was sworn in appropriately.” But out of caution and to ward off any speculation that he wasn’t properly sworn in, aides decided on Wednesday afternoon to give the oath another try.

“The oath appears in the Constitution itself,” Mr. Craig said in a statement. “And out of an abundance of caution, because there was one word out of sequence, Chief Justice Roberts administered the oath a second time.”

At the swearing-in ceremony on Tuesday, Mr. Roberts juxtaposed a word in the oath when he said, “That I will execute the office of president to the United States faithfully.” The word “faithfully” was misplaced.

Mr. Obama, who had been studying his lines, paused awkwardly after saying, “that I will execute.” The chief justice gave it another try, but still not quite right, omitting the word “execute.”

As set out in the Constitution, this is what Mr. Obama should have said:

I do solemnly swear (or affirm) that I will faithfully execute the Office of the President of the United States, and will to the best of my Ability, preserve, protect and defend the Constitution of the United States.

(Like most of his predecessors, Mr. Obama swore, rather than affirmed, and like some past presidents he appended “so help me God” to the standard text.)

During a luncheon after the inauguration ceremony, Mr. Roberts could be seen on camera telling the president that the mistake was “my fault.” So he agreed to travel to the White House on Wednesday evening for a ceremony that was not announced until it was over.