The Gävleborg Police's detention centers in Gävle, Sandviken, Bollnäs and Hudiksvall will be staffed by a private security company starting in March.
About 40 guards are affected.
In recent years, the prison operations have had difficulties with staffing and laborious administration, according to the police.
Chores may be taken over by police officers
John Köhler, head of office at the police in Gävleborg.
The arrangement exists in several parts of the country, but the prison guards' union Seko believes that it leads to increased work for police officers.
Guards employed by the authority are allowed to perform tasks that are important for investigations, which hired personnel are not allowed to do.
These tasks risk ending up on an already overburdened police force, according to the union.
The police, on the other hand, see a gain in having police officers take over parts of the detention guards' duties.
Hear John Köhler from the police in Gävleborg and Seko police chairman Karna Tillheden in the clip above.