A work by the Dutch abstract artist Piet Mondrian was displayed upside down in various galleries for 75 years, an art historian said, according to the BBC.

Despite the recent discovery, the work, titled “New York City I,” will continue to be displayed incorrectly to avoid damage.

The painting, created in 1941, was first exhibited at MoMA in New York in 1945.

Since 1980, it has been exhibited in the art collection of the German state of North Rhine-Westphalia in Düsseldorf.

Curator Suzanne Mayer-Bueser noticed the long-standing error while inspecting the artist’s new museum exhibit earlier this year, but warned that it might fall apart if the correct piece was now hung on the side.

“New York I” is a version of the same artist’s painting “New York” with a similar name. So the top part will be the part where several bands will be grouped together to represent the dark sky.

“The thickening of the grid should be upwards like a dark sky,” Mayer-Bueser told The Guardian of the unfinished and unsigned artwork with red, blue and yellow stripes.

“After we told the other curators, we realized it was very obvious. It is likely that the image is the other way around,” she added when contacted by the BBC.