The subject of the invention is the use of MoO3 as a corrosion inhibitor, and an anti-corrosion coating composition for metal parts, characterized in that it comprises:—at least one particulate metal;—an organic solvent;—a thickener;—a silane-based binder, preferably carrying epoxy functional groups;—molybdenum oxide (MoO3);—possibly a silicate of sodium, potassium or lithium, and;—water.