src/java.base/share/classes/java/net/Inet4Address.java

@@ -87,10 +87,11 @@
     static final int INADDRSZ = 4;
 
     /** use serialVersionUID from InetAddress, but Inet4Address instance
      *  is always replaced by an InetAddress instance before being
      *  serialized */
+    @java.io.Serial
     private static final long serialVersionUID = 3286316764910316507L;
 
     /*
      * Perform initializations.
      */

@@ -132,10 +133,11 @@
      * @return the alternate object to be serialized.
      *
      * @throws ObjectStreamException if a new object replacing this
      * object could not be created
      */
+    @java.io.Serial
     private Object writeReplace() throws ObjectStreamException {
         // will replace the to be serialized 'this' object
         InetAddress inet = new InetAddress();
         inet.holder().hostName = holder().getHostName();
         inet.holder().address = holder().getAddress();