A water-based dispersion sealant composition, including an aqueous polymer dispersion including water and at least one water-dispersible polymer, at least one polyolefin oligomer, at least one hydrogenated mixture of alkanes, isoalkanes, and/or cycloalkanes with a boiling point of at least 150° C., and optionally at least one plasticizer having at least one ester or ether group, wherein the at least one polyolefin oligomer and the at least one hydrogenated mixture of alkanes, isoalkanes, and/or cycloalkanes with a boiling point of at least 150° C. are liquid at 23° C. and under standard pressure, wherein the at least one polyolefin oligomer is selected from polybutene and/or polyisobutylene, and wherein said at least one water-dispersible polymer is selected from poly(meth)acrylate polymers, styrene-(meth)acrylate copolymers, and vinyl-acetate-(meth)acrylate copolymers. The inventive composition is highly suitable as joint sealant or coating and offers reduced surface tackiness, low modulus, also at low temperatures, and good adhesion and water-resistance properties.