diff --git a/src/java.desktop/share/classes/javax/swing/plaf/synth/SynthButtonUI.java b/src/java.desktop/share/classes/javax/swing/plaf/synth/SynthButtonUI.java
index 5a384393793..3a3d5719605 100644
--- a/src/java.desktop/share/classes/javax/swing/plaf/synth/SynthButtonUI.java
+++ b/src/java.desktop/share/classes/javax/swing/plaf/synth/SynthButtonUI.java
@@ -46,8 +46,6 @@ public class SynthButtonUI extends BasicButtonUI implements
                                  PropertyChangeListener, SynthUI {
     private SynthStyle style;
 
-    private static final Object SYNTH_BUTTON_UI_KEY = new Object();
-
     /**
      * Constructs a {@code SynthButtonUI}.
      */