Pope Francis declared in a letter to the Vatican on Thursday that women should be included in foot-washing ceremonies on Holy Thursday during Easter week, opposing centuries of tradition.

The Vatican announced that the change will now be part of the Roman Missal, the book that guides Catholic liturgy throughout the world, and it will take effect on Holy Thursday, March 24, according to CNN.

The ritual takes place in Catholic parishes around the world on Holy Thursday, four days before Easter. Until now, only men or boys were formally allowed to take part in the service, in which a priest washes and kisses the feet of 12 people to commemorate Jesus' gesture of humility toward his apostles on the night before he died, according to Reuters.

"After careful consideration," Francis said in a letter to the Vatican department that regulates rites of worship, "I have decided to make a change to the Roman Missal. I therefore decree that the section according to which those persons chosen for the washing of the feet must be men or boys, so that from now on the pastors of the Church may choose the participants in the rite from among all the members of the People of God."

In practice, many parishes around the world have long included women in the rite, and Francis, himself, broke convention on the first Holy Thursday after his papal election in 2013, when he washed the feet of women prisoners, according to The Catholic Herald.

"This is great news, a wonderful step forward," said Erin Hanna, co-director of the U.S.-based Woman's Ordination Conference, which promotes a female Catholic priesthood.

"This means that change is possible, doors seem to be opening in the Vatican," she told Reuters.