Updating XML documents submitted to schema constraints requires incremental validation, i.e. checking the parts of the document concerned by the updates. We propose to correct subtrees for which re-validation fails: if the validator fails at node p, a correction routine is called in order to compute corrections of the subtree rooted at p, within a given threshold. Then validation continues. In the correction process, we limit ourselves to single typed tree language. The correction routine uses tree edit distance matrices. Different correction versions are proposed to the user.