--- a/dom/svg/SVGUseElement.h
+++ b/dom/svg/SVGUseElement.h
@@ -124,17 +124,16 @@ protected:
   nsSVGLength2 mLengthAttributes[4];
   static LengthInfo sLengthInfo[4];
 
   enum { HREF, XLINK_HREF };
   nsSVGString mStringAttributes[2];
   static StringInfo sStringInfo[2];
 
   nsCOMPtr<nsIContent> mOriginal; // if we've been cloned, our "real" copy
-  nsCOMPtr<nsIContent> mClone;    // cloned tree
   ElementTracker       mReferencedElementTracker;
   RefPtr<URLExtraData> mContentURLData; // URL data for its anonymous content
 };
 
 } // namespace dom
 } // namespace mozilla
 
 #endif // mozilla_dom_SVGUseElement_h