Edvard Munch’s 1893 painting “The Scream" is so famous it has its own emoji. Few works of art are so enshrined in popular culture. From The Simpsons and Home Alone to Bernie Sanders memes and Vans collabs, “The Scream” continues to resonate, yet a tiny inscription on the iconic work has eluded art historians, until today.

The words, "Can only have been painted by a madman," are scrawled in pencil in the top left-hand corner of the painting and until now, no one has been sure who wrote it. Now, new tests made by The National Museum of Norway have confirmed they were made by Munch himself.

There are numerous rumors about the inscription. Many believed the work was vandalized while on show in a gallery; others maintained that it was the artist himself who wrote the cryptic epitaph.

Now, the mystery has come to an end. Curators at Norway’s National Museum of Art, Architecture and Design, which owns the painting, announced Monday in Oslo that they have determined that the text was indeed written by the artist.

According to The New York Times, there's little uncertainty that the message belongs to Munch. “It’s been examined now very carefully, letter by letter, and word by word, and it’s identical in every way to Munch’s handwriting,” said Mai Britt Guleng, the museum’s curator of old masters and modern paintings, who was in charge of the research. “There is no more doubt.”

Considering the painting is so iconic — it's dubbed the Mona Lisa of modern art" and is an enduring symbol of existential angst — the concession that it could "only have been painted by a madman" has plagued art historians. Why would an artist vandalize his own work and if so, why would he write his message so small?

To study it, researchers used infrared photography to make it more legible. “He didn’t write it in big letters for everyone to see,” Guleng said. “You really have to look hard to see it. Had it been an act of vandalism, it would have been larger.”

An 1895 exhibition could hold some answers. Guleng suggests that during a debate about the exhibition at the University of Oslo’s Students Association one night, a medical student named Johan Scharffenberg said the artwork "gave him reason to question the artist’s mental state, calling Munch abnormal and a 'madman.'"

According to Lasse Jacobsen, a research librarian at the Munch Museum in Oslo, Munch was deeply offended by critique and wrote about the "madman" review for decades to come.

Guleng told NYT that, “by writing this inscription in the clouds, he took possession, in a way, or he took control of how he was to be perceived and understood.”