Behavioral specifications which are integrated into component interfaces are an important means for the correct construction of component-based systems. Currently, such specifications are typically limited to finite-state protocols because more expressive notions of protocol do not support reasonable basic composition properties, such as compatibility and substitutability. In this paper, we present first results of the integration into component interfaces of a notion of non-regular protocols based on {``}non-regular process types{''} introduced by Puntigam. More concretely, we present three contributions: (i) a motivation of the usefulness of non-regular protocols in the context of peer-to-peer applications, (ii) a language for non-regular protocols and an outline of a suitable formal definition, (iii) a discussion of basic composition properties and an analysis of how to adequately integrate protocol-modifying operators in the model.