src/java.base/share/classes/java/time/Year.java

*** 145,154 ****
--- 145,155 ----
      public static final int MAX_VALUE = 999_999_999;
  
      /**
       * Serialization version.
       */
+     @java.io.Serial
      private static final long serialVersionUID = -23038383694477807L;
      /**
       * Parser.
       */
      private static final DateTimeFormatter PARSER = new DateTimeFormatterBuilder()
*** 1095,1114 ****
--- 1096,1117 ----
       *  out.writeInt(year);
       * </pre>
       *
       * @return the instance of {@code Ser}, not null
       */
+     @java.io.Serial
      private Object writeReplace() {
          return new Ser(Ser.YEAR_TYPE, this);
      }
  
      /**
       * Defend against malicious streams.
       *
       * @param s the stream to read
       * @throws InvalidObjectException always
       */
+     @java.io.Serial
      private void readObject(ObjectInputStream s) throws InvalidObjectException {
          throw new InvalidObjectException("Deserialization via serialization delegate");
      }
  
      void writeExternal(DataOutput out) throws IOException {