The invention relates to a one-component powder coating composition comprising a curing system comprising a curable resin and one or more curing additives for curing the curable resin, wherein the powder coating composition comprises: - one powder coating component comprising the curable resin and the one or more curing additives; and - in the range of from 0.5 to 25 wt% of a dry-blended inorganic particulate additive consisting of inorganic components i), ii), and iii), wherein component i) is non-coated aluminium oxide or non-coated silica, component ii) is aluminium hydroxide and/or aluminum oxyhydroxide, and component iii) is silica, and wherein, if component i) is non-coated silica, component iii) does not comprise non-coated silica, wherein the dry-blended inorganic particulate additive comprises a first and a second silica wherein the first silica is a surface-treated silica with a negative tribocharge, and the second silica is non-coated silica or is a surface-treated silica with a positive tribocharge wherein the wt% of the dry-blended inorganic additive is based on the weight of the one powder coating component, and wherein the powder coating component has a particle size distribution with a Dv90 of at most 50 µm and a Dv50 of at most 30 µm, wherein Dv90 and Dv50 are determined by laser diffraction according to ISO 13320 using the Mie model. The invention further relates to a substrate coated with such powder coating composition.