Any implementation of an information system must ensure that an operation is only applied if its execution does not lead to a violation of any of the integrity constraints defined in its conceptual schema. In this paper we propose a method to automatically determine the operations that may potentially violate an OCL integrity constraint in conceptual schemas defined in the UML. This is done by determining the structural events that may violate the constraint and checking whether those events appear in the operation specification. In this way, our method helps to improve efficiency of integrity checking since its results can be used to discard many irrelevant tests.