Washington ? President Barack Obama took the oath of office Tuesday outside the Capitol, as millions watched in person and on TV. He took it again Wednesday night — this time in the privacy of the White House, with only a handful of aides and reporters looking on.

The reason: During the inauguration ceremony, Chief Justice John G. Roberts Jr. stumbled over the oath’s opening words, and Obama repeated them back, incorrectly.

The second time around, they both got it right.

The president’s lawyer and constitutional experts agreed that taking the oath a second time was unnecessary. Under the Constitution, Obama became president at noon Tuesday, a few minutes before he placed his hand on a Bible to take the oath.

“We believe the oath of office was administered effectively and that the president was sworn in appropriately yesterday,” White House counsel Greg Craig said in a statement. “But the oath appears in the Constitution itself. And out of abundance of caution, because there was one word out of sequence, Chief Justice Roberts administered the oath a second time.”