Damage due to salt crystallization is a ubiquitous problem in porous building materials. Crystallizing salts can cause severe damage to building materials. Especially lime-based mortars, which are often found in historic buildings, are prone to salt damage due to their pore size distribution and limited mechanical strength. Renovation costs for replacing or repairing materials affected by salt crystallization damage are considerable. Existing solutions, such as cement-based salt-resistant plasters with mixed-in water-repellent additives, generally have a low compatibility with the existing materials. Where the current methods are based on increasing the strength of the material or on limiting the ingress of (salt-laden) water into the porous material, our method is to tackle the problem at its base, by modifying the crystallization of the salts. By influencing the crystallization process with special chemicals, so called crystallization modifiers, salt crystallization on the surface of the material instead of in the pores or at a lower supersaturation level is favoured. Both are factors which limit crystallization damage. By mixing-in the crystallization modifiers in a lime-based mortar before its application, a smart self-healing (restoration) product can be made which will act at the moment the salts are expected to cause damage, i.e. at the onset of crystallization. Our proposed method could therefore result in a longer service-life of buildings and, consequently, in lower restoration costs.