diff --git a/dom/base/Document.cpp b/dom/base/Document.cpp
index cc1e57e57cdc..157fcd799700 100644
--- a/dom/base/Document.cpp
+++ b/dom/base/Document.cpp
@@ -7810,18 +7810,6 @@ Element* Document::GetBindingParent(nsINode& aNode) {
   return bindingParent ? bindingParent->AsElement() : nullptr;
 }
 
-Element* Document::GetAnonymousElementByAttribute(
-    nsIContent* aElement, nsAtom* aAttrName,
-    const nsAString& aAttrValue) const {
-  return nullptr;
-}
-
-Element* Document::GetAnonymousElementByAttribute(Element& aElement,
-                                                  const nsAString& aAttrName,
-                                                  const nsAString& aAttrValue) {
-  return nullptr;
-}
-
 nsINodeList* Document::GetAnonymousNodes(Element& aElement) { return nullptr; }
 
 already_AddRefed<nsRange> Document::CreateRange(ErrorResult& rv) {
diff --git a/dom/base/Document.h b/dom/base/Document.h
index f566a0ae4145..00605687b3d2 100644
--- a/dom/base/Document.h
+++ b/dom/base/Document.h
@@ -2745,10 +2745,6 @@ class Document : public nsINode,
    */
   bool HaveFiredDOMTitleChange() const { return mHaveFiredTitleChange; }
 
-  Element* GetAnonymousElementByAttribute(nsIContent* aElement,
-                                          nsAtom* aAttrName,
-                                          const nsAString& aAttrValue) const;
-
   /**
    * To batch DOMSubtreeModified, document needs to be informed when
    * a mutation event might be dispatched, even if the event isn't actually
@@ -3713,9 +3709,6 @@ class Document : public nsINode,
 
   // QuerySelector and QuerySelectorAll already defined on nsINode
   nsINodeList* GetAnonymousNodes(Element& aElement);
-  Element* GetAnonymousElementByAttribute(Element& aElement,
-                                          const nsAString& aAttrName,
-                                          const nsAString& aAttrValue);
   Element* GetBindingParent(nsINode& aNode);
 
   XPathExpression* CreateExpression(const nsAString& aExpression,
diff --git a/dom/webidl/Document.webidl b/dom/webidl/Document.webidl
index 11ffebe28591..edf08a3f7972 100644
--- a/dom/webidl/Document.webidl
+++ b/dom/webidl/Document.webidl
@@ -382,9 +382,6 @@ partial interface Document {
   [Func="IsChromeOrXBL"]
   NodeList? getAnonymousNodes(Element elt);
   [Func="IsChromeOrXBL"]
-  Element? getAnonymousElementByAttribute(Element elt, DOMString attrName,
-                                          DOMString attrValue);
-  [Func="IsChromeOrXBL"]
   Element? getBindingParent(Node node);
   // Creates a new XUL element regardless of the document's default type.
   [CEReactions, NewObject, Throws, Func="IsChromeOrXBL"]
diff --git a/js/xpconnect/tests/mochitest/test_bug912322.html b/js/xpconnect/tests/mochitest/test_bug912322.html
index c6918d5c450f..f553c730b7e0 100644
--- a/js/xpconnect/tests/mochitest/test_bug912322.html
+++ b/js/xpconnect/tests/mochitest/test_bug912322.html
@@ -11,8 +11,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=912322
   <script type="application/javascript">
 
   /** Test that XBL functions aren't exposed to the web. **/
-  funs = ['getAnonymousNodes', 'getAnonymousElementByAttribute',
-          'getBindingParent'];
+  funs = ['getAnonymousNodes', 'getBindingParent'];
   for (var f of funs) {
     ok(!(f in document), f + " should not be available to content");
     ok(f in SpecialPowers.wrap(document), f + " should be available to chrome via Xray");