Abstract: The invention relates to a process for the treatment of cellulosic moulded bodies which are formed from a solution of cellulose in an aqueous tertiary amine oxide, particularly fibers, whereby the moulded bodies are brought into contact with an aqueous solution of a textile auxiliary agent which bears two reactive groups in the alkaline milieu. The invention is characterised in that as the textile auxiliary agent, a compound of formula whereby X is halogen, R═H or an ionic residue and n=0 or 1, respectively a salt of this compound is used. The invention also relates to the use of compounds of this formula to reduce the tendency to fibrillate and to increase the UV absorption of solvent-spun fibers.