src/java.base/share/classes/java/time/chrono/Ser.java

*** 92,101 ****
--- 92,102 ----
  final class Ser implements Externalizable {
  
      /**
       * Serialization version.
       */
+     @java.io.Serial
      private static final long serialVersionUID = -6103370247208168577L;
  
      static final byte CHRONO_TYPE = 1;
      static final byte CHRONO_LOCAL_DATE_TIME_TYPE = 2;
      static final byte CHRONO_ZONE_DATE_TIME_TYPE = 3;
*** 247,256 ****
--- 248,258 ----
      /**
       * Returns the object that will replace this one.
       *
       * @return the read object, should never be null
       */
+     @java.io.Serial
      private Object readResolve() {
           return object;
      }
  
  }