The invention provides a chemical-mechanical polishing composition comprising, consisting essentially of, or consisting of (a) about 0.01 wt. % to about 1 wt. % of wet-process ceria, (b) about 10 ppm to about 200 ppm of a cationic polymer comprising quaternary amino groups, (c) about 10 ppm to about 2000 ppm of a non-fluorinated nonionic surfactant, (d) an amino acid, and (e) water, wherein the polishing composition has a pH of about 3 to about 8. The invention further provides a method of polishing a substrate with the polishing composition.