diff --git a/user/src/com/google/gwt/user/client/ui/CustomButton.java b/user/src/com/google/gwt/user/client/ui/CustomButton.java
index 93f4902..44d699d 100644
--- a/user/src/com/google/gwt/user/client/ui/CustomButton.java
+++ b/user/src/com/google/gwt/user/client/ui/CustomButton.java
@@ -96,8 +96,7 @@
  * </p>
  * 
  */
-public abstract class CustomButton extends ButtonBase implements
-    SourcesKeyboardEvents {
+public abstract class CustomButton extends ButtonBase {
   /**
    * Represents a button's face. Each face is associated with its own style
    * modifier and, optionally, its own contents html, text, or image.