diff --git a/dom/xul/nsXULPrototypeDocument.cpp b/dom/xul/nsXULPrototypeDocument.cpp
index 68d1148ed828..345e2a0aede7 100644
--- a/dom/xul/nsXULPrototypeDocument.cpp
+++ b/dom/xul/nsXULPrototypeDocument.cpp
@@ -438,24 +438,6 @@ nsXULPrototypeDocument::GetStyleSheetReferences() const
     return mStyleSheetReferences;
 }
 
-NS_IMETHODIMP
-nsXULPrototypeDocument::GetHeaderData(nsAtom* aField, nsAString& aData) const
-{
-    // XXX Not implemented
-    aData.Truncate();
-    return NS_OK;
-}
-
-
-NS_IMETHODIMP
-nsXULPrototypeDocument::SetHeaderData(nsAtom* aField, const nsAString& aData)
-{
-    // XXX Not implemented
-    return NS_OK;
-}
-
-
-
 nsIPrincipal*
 nsXULPrototypeDocument::DocumentPrincipal()
 {
diff --git a/dom/xul/nsXULPrototypeDocument.h b/dom/xul/nsXULPrototypeDocument.h
index 5ffca8aa38a4..adf8ac767d27 100644
--- a/dom/xul/nsXULPrototypeDocument.h
+++ b/dom/xul/nsXULPrototypeDocument.h
@@ -82,13 +82,6 @@ public:
     void AddStyleSheetReference(nsIURI* aStyleSheet);
     const nsCOMArray<nsIURI>& GetStyleSheetReferences() const;
 
-    /**
-     * Access HTTP header data.
-     * @note Not implemented.
-     */
-    NS_IMETHOD GetHeaderData(nsAtom* aField, nsAString& aData) const;
-    NS_IMETHOD SetHeaderData(nsAtom* aField, const nsAString& aData);
-
     nsIPrincipal *DocumentPrincipal();
     void SetDocumentPrincipal(nsIPrincipal *aPrincipal);