This article proposes and describes JPIAspectZ, a formal language used to write AspectOriented (AO) software specification to support the use of Join Point Interfaces (JPI) between advised classes and aspects. JPIAspectZ looks for a concept and model consistency for a JPI software development process. The main characteristic of JPI is to define explicit associations between aspects and advised classes by means of join point interfaces, so that classes are no longer oblivious of their possible interaction with aspects and as well aspects, for their action effectiveness, do not depend on signatures of advisable class methods. Only JPIAspectZ supports this JPI principle. An application example of JPIAspectZ is presented to analyze the pros and cons of our proposal.