src/java.desktop/share/classes/javax/swing/JComponent.java

@@ -616,10 +616,11 @@
      * Returns the look and feel delegate that renders this component.
      *
      * @return the {@code ComponentUI} object that renders this component
      * @since 1.9
      */
+    @Transient
     public ComponentUI getUI() {
         return ui;
     }
 
     /**