We present a way of specifying software components that is suitable for checking their interoperability. Our specification approach is independent of concrete specification languages. It stresses the necessity of equipping each component interface with a suitable data model. That data model defines all types occurring in the signature of interface operations. Moreover, pre- and postconditions have to be given for all interface operations. Finally, the order in which the interface operations may be invoked must be specified. A notion of compatibility -- which is based on specification matching -- makes it possible to check if two components can interoperate or not.