Collaborative writing is the process of two or more people working together to create a common document. People can be distributed in time, in place and across organizations. They can share writing different kinds of documents. In this paper, we focus on collaborative writing of XML documents. XML documents must be validated via a set of constraints called DTD to be considered as consistent. In cooperative writing, shared XML documents are replicated on different sites. This improves the availability of the documents. The modifications of a replica at a site are sent and integrated on all the others sites, in order to ensure the convergence of the replicas. While on each site, a replica can be validated via the DTD. After the reconciliation (also known as merging) of the different replicas, the result of merging consistent replicas may not validate the DTD. A major problem of this result, that is not possible to open a document with the tool used to edit it. To overcome this problem, we propose an automatic approach to repair inconsistency.