 During World War II, on 15 August 1943, the refectory was struck by Allied bombing; protective sandbagging prevented the painting from being struck by bomb splinters, but it may have been damaged by the vibration.Between 1946 and 1954, undertook a clean-and-stabilise restoration, which Brera director was involved in.Pellicioli reattached paint to the wall using a clear shellac, making it relatively darker and more colorful, and removed some of the overpainting.