Compositions comprising silane-crosslinking polymers of the formula Y-[(CR 1 2) b -SiR a (OR 2) 3-a] x, where Y represents a polymer residue which is x-valent and attached via nitrogen, oxygen, sulfur or carbon, selected from polyurethane residues and polyoxyalkylene residues, R represents a monovalent, optionally substituted hydrocarbyl radical and may be the same or different in each occurrence, R 1 represents the hydrogen atom or a monovalent, optionally substituted hydrocarbyl radical which may be attached to the carbon atom via nitrogen, phosphorus, oxygen, sulfur or a carbonyl group and may be the same or different in each occurrence, R 2 represents a hydrogen atom or a monovalent, optionally substituted hydrocarbyl radical and may be the same or different in each occurrence, x represents an integer from 1 to 10, a represents 0, 1 or 2 and may be the same or different in each occurrence, and b represents an integer from 1 to 10 and may be the same or different in each occurrence, finely divided silica, and basic nitrogen organosilicon compound comprising units of the formula D c Si(OR 3) d R 4 e O (4-c-d-e)/2, where R 3 represents a hydrogen atom or optionally substituted hydrocarbyl radicals and may be the same or different in each occurrence, D represents a monovalent SiC-bonded radical with basic nitrogen and may be the same or different in each occurrence, R 4 represents a monovalent, optionally substituted SiC-bonded organic radical free from basic nitrogen and may be the same of different in each occurrence, c represents 0, 1, 2, 3 or 4, preferably 1, d represents 0, 1, 2 or 3, preferably 1, 2 or 3, more preferably 2 or 3, and e represents 0, 1, 2 or 3, preferably 1 or 0, with the proviso that the sum total of c+d+e is not more than 4 and at least one D radical is present per molecule, with the proviso that silane-crosslinking polymers have an average molar mass M n (number average) of at least 8000 g/mol and at most 30 000 g/mol and that composition comprises finely divided silica in an amount of 16 to 50 wt%, based on the overall weight of composition. silane-crosslinking polymers of the formula Y-[(CR 1 2) b -SiR a (OR 2) 3-a] x, where Y represents a polymer residue which is x-valent and attached via nitrogen, oxygen, sulfur or carbon, selected from polyurethane residues and polyoxyalkylene residues, R represents a monovalent, optionally substituted hydrocarbyl radical and may be the same or different in each occurrence, R 1 represents the hydrogen atom or a monovalent, optionally substituted hydrocarbyl radical which may be attached to the carbon atom via nitrogen, phosphorus, oxygen, sulfur or a carbonyl group and may be the same or different in each occurrence, R 2 represents a hydrogen atom or a monovalent, optionally substituted hydrocarbyl radical and may be the same or different in each occurrence, x represents an integer from 1 to 10, a represents 0, 1 or 2 and may be the same or different in each occurrence, and b represents an integer from 1 to 10 and may be the same or different in each occurrence, Y represents a polymer residue which is x-valent and attached via nitrogen, oxygen, sulfur or carbon, selected from polyurethane residues and polyoxyalkylene residues, R represents a monovalent, optionally substituted hydrocarbyl radical and may be the same or different in each occurrence, R 1 represents the hydrogen atom or a monovalent, optionally substituted hydrocarbyl radical which may be attached to the carbon atom via nitrogen, phosphorus, oxygen, sulfur or a carbonyl group and may be the same or different in each occurrence, R 2 represents a hydrogen atom or a monovalent, optionally substituted hydrocarbyl radical and may be the same or different in each occurrence, x represents an integer from 1 to 10, a represents 0, 1 or 2 and may be the same or different in each occurrence, and b represents an integer from 1 to 10 and may be the same or different in each occurrence, finely divided silica, and basic nitrogen organosilicon compound comprising units of the formula D c Si(OR 3) d R 4 e O (4-c-d-e)/2, where R 3 represents a hydrogen atom or optionally substituted hydrocarbyl radicals and may be the same or different in each occurrence, D represents a monovalent SiC-bonded radical with basic nitrogen and may be the same or different in each occurrence, R 4 represents a monovalent, optionally substituted SiC-bonded organic radical free from basic nitrogen and may be the same of different in each occurrence, c represents 0, 1, 2, 3 or 4, preferably 1, d represents 0, 1, 2 or 3, preferably 1, 2 or 3, more preferably 2 or 3, and e represents 0, 1, 2 or 3, preferably 1 or 0, with the proviso that the sum total of c+d+e is not more than 4 and at least one D radical is present per molecule, R 3 represents a hydrogen atom or optionally substituted hydrocarbyl radicals and may be the same or different in each occurrence, D represents a monovalent SiC-bonded radical with basic nitrogen and may be the same or different in each occurrence, R 4 represents a monovalent, optionally substituted SiC-bonded organic radical free from basic nitrogen and may be the same of different in each occurrence, c represents 0, 1, 2, 3 or 4, preferably 1, d represents 0, 1, 2 or 3, preferably 1, 2 or 3, more preferably 2 or 3, and e represents 0, 1, 2 or 3, preferably 1 or 0,