src/java.base/share/classes/java/io/UncheckedIOException.java

@@ -30,10 +30,11 @@
  * Wraps an {@link IOException} with an unchecked exception.
  *
  * @since   1.8
  */
 public class UncheckedIOException extends RuntimeException {
+    @java.io.Serial
     private static final long serialVersionUID = -8134305061645241065L;
 
     /**
      * Constructs an instance of this class.
      *

@@ -77,10 +78,11 @@
      *
      * @throws  InvalidObjectException
      *          if the object is invalid or has a cause that is not
      *          an {@code IOException}
      */
+    @java.io.Serial
     private void readObject(ObjectInputStream s)
         throws IOException, ClassNotFoundException
     {
         s.defaultReadObject();
         Throwable cause = super.getCause();