The Musée Picasso reopening has been delayed until sometime in September, according to the Culture Ministry, a move that has left Pablo Picasso's son not at all happy.

The museum has been under renovation for the past four years and has already had several delays before the latest, reports The New York Times. The work has so far cost about $72 million.

Part of the delay is due to the technical building not being finished, which is important as it will be where the important climate control system will be kept. A French official, who commented anonymously, said, "We don't open a museum if we aren't sure about the climate control; it is fundamental." They added, "All this is very common. It happened for many other museums.

The delay from a June reopening has left Picasso's son, Claude Picasso, quite upset, according to The Chicago Tribune. "I am outraged and deeply concerned," the 66-year-old told French newspaper Le Figaro. "I get the impression that France couldn't give a damn about my father or me."

The Musée Picasso first opened back in 1985 and houses about 300 paintings from Picasso and hundreds more sculptures and other works.

The Culture Ministry released a statement trying to calm those upset with the delays urging "everyone to put their own personal interests to one side and share the enthusiasm and calm required to complete this project."