diff a/src/java.base/share/classes/java/security/cert/CertPathValidatorException.java b/src/java.base/share/classes/java/security/cert/CertPathValidatorException.java
--- a/src/java.base/share/classes/java/security/cert/CertPathValidatorException.java
+++ b/src/java.base/share/classes/java/security/cert/CertPathValidatorException.java
@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2021, 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
@@ -227,10 +227,17 @@
      */
     public Reason getReason() {
         return this.reason;
     }
 
+    /**
+     * Restores the state of this object from the stream.
+     *
+     * @param  stream 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 stream)
         throws ClassNotFoundException, IOException {
         stream.defaultReadObject();
         if (reason == null) {
