diff a/src/java.base/share/classes/java/lang/Throwable.java b/src/java.base/share/classes/java/lang/Throwable.java
--- a/src/java.base/share/classes/java/lang/Throwable.java
+++ b/src/java.base/share/classes/java/lang/Throwable.java
@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 1994, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1994, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Oracle designates this
@@ -900,10 +900,14 @@
      * stackTrace} field.
      *
      * Note that there are no constraints on the value the {@code
      * cause} field can hold; both {@code null} and {@code this} are
      * valid values for the field.
+     *
+     * @param  s the {@code ObjectInputStream} from which data is read
+     * @throws IOException if an I/O error occurs
+     * @throws ClassNotFoundException if a serialized class cannot be loaded
      */
     @java.io.Serial
     private void readObject(ObjectInputStream s)
         throws IOException, ClassNotFoundException {
         s.defaultReadObject();     // read in all fields
@@ -989,10 +993,13 @@
      * Write a {@code Throwable} object to a stream.
      *
      * A {@code null} stack trace field is represented in the serial
      * form as a one-element array whose element is equal to {@code
      * new StackTraceElement("", "", null, Integer.MIN_VALUE)}.
+     *
+     * @param  s the {@code ObjectOutputStream} to which data is written
+     * @throws IOException if an I/O error occurs
      */
     @java.io.Serial
     private synchronized void writeObject(ObjectOutputStream s)
         throws IOException {
         // Ensure that the stackTrace field is initialized to a
