diff --git a/editor/libeditor/EditorBase.h b/editor/libeditor/EditorBase.h
index c16352daefac..d590fc4c57a9 100644
--- a/editor/libeditor/EditorBase.h
+++ b/editor/libeditor/EditorBase.h
@@ -119,6 +119,7 @@ class JoinNodeTransaction;
 class RemoveStyleSheetTransaction;
 class SplitNodeTransaction;
 class TextComposition;
+class TextEditor;
 struct EditorDOMPoint;
 
 namespace dom {
@@ -164,6 +165,9 @@ public:
    */
   EditorBase();
 
+  virtual TextEditor* AsTextEditor() = 0;
+  virtual const TextEditor* AsTextEditor() const = 0;
+
 protected:
   /**
    * The default destructor. This should suffice. Should this be pure virtual
diff --git a/editor/libeditor/HTMLEditor.cpp b/editor/libeditor/HTMLEditor.cpp
index 519c147535c0..843c855c4fa5 100644
--- a/editor/libeditor/HTMLEditor.cpp
+++ b/editor/libeditor/HTMLEditor.cpp
@@ -510,7 +510,7 @@ HTMLEditor::InitRules()
     // instantiate the rules for the html editor
     mRules = new HTMLEditRules();
   }
-  return mRules->Init(static_cast<TextEditor*>(this));
+  return mRules->Init(this);
 }
 
 NS_IMETHODIMP
diff --git a/editor/libeditor/TextEditor.h b/editor/libeditor/TextEditor.h
index 8cc035caa146..bc7f03d9ddd9 100644
--- a/editor/libeditor/TextEditor.h
+++ b/editor/libeditor/TextEditor.h
@@ -56,6 +56,9 @@ public:
 
   TextEditor();
 
+  virtual TextEditor* AsTextEditor() override { return this; }
+  virtual const TextEditor* AsTextEditor() const override { return this; }
+
   // nsIPlaintextEditor methods
   NS_DECL_NSIPLAINTEXTEDITOR