The art gallery where thieves stole The Scream last month is to upgrade its security in the wake of the raid.
The Munch Museum's security was heavily criticised after the raid
Security at the Munch Museum in Oslo, Norway, was criticised after armed robbers ripped Edvard Munch's masterpiece off the wall.
"We will install a new surveillance alarm. This was planned before the theft of The Scream, but we have now concluded talks," a spokesperson said.
The Scream and another Munch painting, Madonna, are still missing.
Two armed, masked men carried out the raid in daylight in full view of visitors on 22 August.
The gallery's director had defended security, saying a silent alarm went off and police arrived within minutes.
Edvard Munch's The Scream is an iconic image of loneliness
"We are closed and will be closed for three weeks to install alarms, among other things," a museum official said.
The Norwegian press was dismayed by the ease of the robbery.
"Almost as easy as robbing a kiosk," said a front-page headline in the national broadsheet Aftenposten.
Oslo's Dagbladet made the point that "some of our national treasures are too poorly protected".
The Scream was insured for fire or water damage - but not theft.
Police have not made any arrests or announced major progress in the case.
Another version of The Scream was stolen from Oslo's National Art Museum in 1994, when thieves set off an alarm that was ignored by the guard.
A note was left reading: "Thanks for the poor security."