The JVM spec 9 adds two constant types: module and package: - https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html#jvms-4.4.11 - https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html#jvms-4.4.12 The parse should not fail on those new constants.