Self-healing corrosion protection is provided by functional polyoxometalate ionic liquids (POM-ILs) coated onto metal surfaces. In their Communication on page 13596 ff., C. Streb et al. utilize POM-ILs, which are hydrophobic, acid-resistant, and form mechanically stable films, to protect copper metal against acid corrosion. Mechanical damage to the coating is self-repaired in less than one minute through the unique rheological properties of the compounds.