U.S. Senator-elect Doug Jones is set to be sworn into office Wednesday in Washington.

Vice President Mike Pence will administer the oath, which

allows Jones to partake in Senate business.

He will become the 49th Democratic member of the Senate (Independent Sen. Bernie Sanders caucuses with Democrats), tightening the Republican majority in the upper chamber.

Jones became the first Democrat in 25 years to win a Senate seat in Alabama when he defeated Republican Roy Moore in the Dec. 12 special election to fill Jeff Sessions’s seat.