We discuss the development of an OCL specification for the Java Card API. The main purpose of this specification is to support and aid the verification of Java Card programs in the KeY system. The main goal of the KeY system is to integrate object oriented design and formal methods. The already existing specification written in JML (Java Modelling Language) has been used as a starting point for the development of the OCL specification. In this paper we report on the problems that we encountered when writing the specification and their solutions, we present the most interesting parts of the specification, we report on successful verification attempts and finally we evaluate OCL and compare it to JML in the context of Java Card program specification and verification.