--- old/src/java.desktop/share/classes/java/awt/event/MouseAdapter.java	2020-08-05 16:55:45.704264400 -0700
+++ new/src/java.desktop/share/classes/java/awt/event/MouseAdapter.java	2020-08-05 16:55:45.125134700 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1996, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1996, 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
@@ -68,6 +68,12 @@
  * @since 1.1
  */
 public abstract class MouseAdapter implements MouseListener, MouseWheelListener, MouseMotionListener {
+
+    /**
+     * Constructs a {@code MouseAdapter}.
+     */
+    protected MouseAdapter() {}
+
     /**
      * {@inheritDoc}
      */