src/java.base/share/classes/com/sun/java/util/jar/pack/ClassReader.java

*** 603,612 ****
--- 603,613 ----
          cls.innerClasses = ics;  // set directly; do not use setInnerClasses.
          // (Later, ics may be transferred to the pkg.)
      }
  
      static class ClassFormatException extends IOException {
+         @java.io.Serial
          private static final long serialVersionUID = -3564121733989501833L;
  
          public ClassFormatException(String message) {
              super(message);
          }