A foundation has asked people to stop using blackface as part of the traditional 'Star Boys' performance, which tells the bible story of the three wise men and their role in Christian nativity plays.
The foundation said it had taken note of the reaction in wider society to racism, and wanted to show that it takes the message seriously.
Traditionally, one of the 'three kings' has worn blackface in the Oulu telling of the tale. The first record of this tradition dates back to 1873.
Originally groups of youths would travel around a district or area performing the story, asking for donations at the end of the performance. They were known as 'Tiernapojat', or 'Star Boys'.
Blackface has gained notoriety as a way for white actors to portray black characters in often stereotypical or offensive ways.
The Star Boy foundation (Tiernasäätiö in Finnish) says that it would like those performing the ritual outside its own events to take note of its stance and change their ways.
The foundation had recommended that blackface not be used, and that the 'King of the Moors' character be renamed as 'King of the Mauris', after the popular Finnish male name, Mauri.
Now the organisation has said it will not allow blackface at its own events and recommends others follow its lead.
That entails darkening beards below the nose, but not full blackface — but only for male actors.
The foundation organises a Star Boy competition in Oulu city centre on the last weekend of November, where groups from across the country gather to compete.