Antifreeze concentrate with corrosion protection which is suitable for coolants and heat transfer fluids and comprises freezing point-lowering liquids and also particular sulfur-comprising organic compounds, inorganic molybdate salts, inorganic phosphate salts and aliphatic, cycloaliphatic or aromatic monocarboxylic, dicarboxylic or tricarboxylic acids as corrosion inhibitors. Aqueous coolant compositions which are suitable for cooling an internal combustion engine whose cooling apparatus has been made of aluminum using a soldering process using a fluoroaluminate flux can be obtained therefrom.