diff --git a/widget/public/nsITreeDMWidget.h b/widget/public/nsITreeDMWidget.h
new file mode 100644
index 000000000000..326f71426df1
--- /dev/null
+++ b/widget/public/nsITreeDMWidget.h
@@ -0,0 +1,38 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * The contents of this file are subject to the Netscape Public License
+ * Version 1.0 (the "NPL"); you may not use this file except in
+ * compliance with the NPL.  You may obtain a copy of the NPL at
+ * http://www.mozilla.org/NPL/
+ *
+ * Software distributed under the NPL is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
+ * for the specific language governing rights and limitations under the
+ * NPL.
+ *
+ * The Initial Developer of this code under the NPL is Netscape
+ * Communications Corporation.  Portions created by Netscape are
+ * Copyright (C) 1998 Netscape Communications Corporation.  All Rights
+ * Reserved.
+ */
+
+#ifndef nsITreeDMWidget_h___
+#define nsITreeDMWidget_h___
+
+#include "nsIDMWidget.h"
+#include "nsGUIEvent.h"
+
+class nsIDataModel;
+
+// {FC41CD61-796E-11d2-BF86-00105A1B0627}
+#define NS_ITREEDMWIDGET_IID      \
+{ 0xfc41cd61, 0x796e, 0x11d2, { 0xbf, 0x86, 0x0, 0x10, 0x5a, 0x1b, 0x6, 0x27 } }
+
+class nsITreeDMWidget : public nsIDMWidget
+{
+
+public:
+};
+
+#endif /* nsITreeDMWidget_h___ */
+