Toner compositions comprising toner particles including additive particles upon an external surface of the toner particles, wherein the additive particles include crosslinked styrene containing polymer particles, exhibit reduced sensitivity to relative humidity. The crosslinked styrene containing polymer particles preferably have an average particle size of from about 30 nm to about 300 nm, and may comprise styrene homopolymer particles, styrene copolymer particles or mixtures thereof. A process of reducing the relative humidity sensitivity of toner using such external surface additive is also described.