--- old/src/java.base/share/classes/java/lang/reflect/UndeclaredThrowableException.java	2019-08-27 17:27:53.478324386 -0700
+++ new/src/java.base/share/classes/java/lang/reflect/UndeclaredThrowableException.java	2019-08-27 17:27:53.210324386 -0700
@@ -62,6 +62,7 @@
  * @since       1.3
  */
 public class UndeclaredThrowableException extends RuntimeException {
+    @java.io.Serial
     static final long serialVersionUID = 330127114055056639L;
 
     /**
@@ -108,6 +109,7 @@
      *
      * @serialField undeclaredThrowable Throwable
      */
+    @java.io.Serial
     private static final ObjectStreamField[] serialPersistentFields = {
         new ObjectStreamField("undeclaredThrowable", Throwable.class)
     };
@@ -117,6 +119,7 @@
      * and initialize the cause properly when deserializing from an older
      * version.
      */
+    @java.io.Serial
     private void readObject(ObjectInputStream s) throws IOException, ClassNotFoundException {
         ObjectInputStream.GetField fields = s.readFields();
         Throwable exception = (Throwable) fields.get("undeclaredThrowable", null);
@@ -129,6 +132,7 @@
      * To maintain compatibility with older implementation, write a serial
      * "ex" field with the cause as the value.
      */
+    @java.io.Serial
     private void writeObject(ObjectOutputStream out) throws IOException {
         ObjectOutputStream.PutField fields = out.putFields();
         fields.put("undeclaredThrowable", super.getCause());