One of Johannes Vermeer’s most famous paintings had a whimsical element long-ago painted over, and not by the Dutch master himself.

Girl Reading a Letter at an Open Window originally included a naked cupid hovering above the female subject. Detected by X-ray four decades ago, the cupid has recently been established in tests to have been painted over much later by another hand, and not by the artist as once thought. 

The overpainting took place well after the artist’s death in 1675, according to restorers at Staatliche Kunstsammlungen Dresden in Germany. Now, the painting will be fully restored (in about a year) and the cupid revealed.

A hovering cupid signifies that Vermeer intended for the painting to depict a woman reading a love letter.