I'm developing a consumer for my application which run on Java 6 which is calling a remote provider application which runs on Java 7. This throws the following Exception: Caused by: java.lang.UnsupportedClassVersionError: com/company/package/EPCSecurityServices_kkggls_EPCSecurityServicesRIntf : Unsupported major.minor version 51.0 Please advise if it is possible to overcome this problem without upgrading the client application to Java 7.