Composition including at least one polymer containing silane groups and at least one zinc(II) complex compound of Znk(L)x(Y)2k-nx, where k is an integer from 1-10, x is 1, 2, 3, or 4, n corresponds to of ligand L, Y is ligand having −1 charge, and L is ligand of where n is 1, 2, or 3, A is R4 or polyoxyalkylene group or group of polyoxyalkylated compound optionally having one or two terminal 1,3-ketoamide groups, R1 and R2 are hydrogen residue or monovalent saturated or unsaturated hydrocarbon group having 1-10 carbon atoms independently of each other or jointly bivalent alkylene group having 3-6 carbon atoms; R3 and R4 are hydrogen residue or monovalent saturated hydrocarbon group having 1-12 carbon atoms independently of each other, hydrocarbon group optionally contains one or more heteroatoms, or jointly bivalent alkylene group having 3-6 carbon atoms, which alkylene group optionally contains one or more heteroatoms. The invention further relates to the use of the zinc(II) complex compound of the formula Znk(L)x(Y)2k-nx as a catalyst for the cross-linking of polymers containing silane groups by means of moisture.