diff --git a/content/xbl/public/nsIXBLBindingAttachedHandler.h b/content/xbl/public/nsIXBLBindingAttachedHandler.h
new file mode 100644
index 000000000000..666f614018d9
--- /dev/null
+++ b/content/xbl/public/nsIXBLBindingAttachedHandler.h
@@ -0,0 +1,48 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ *
+ * The contents of this file are subject to the Netscape Public
+ * License Version 1.1 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of
+ * the License at http://www.mozilla.org/NPL/
+ *
+ * Software distributed under the License is distributed on an "AS
+ * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * rights and limitations under the License.
+ *
+ * The Original Code is Mozilla Communicator client code.
+ *
+ * The Initial Developer of the Original Code is Netscape Communications
+ * Corporation.  Portions created by Netscape are
+ * Copyright (C) 1998 Netscape Communications Corporation. All
+ * Rights Reserved.
+ *
+ * Original Author: David W. Hyatt (hyatt@netscape.com)
+ *
+ * Contributor(s): 
+ */
+
+/*
+
+  Private interface to the XBL Binding Attached handler
+
+*/
+
+#ifndef nsIXBLBindingAttachedHandler_h__
+#define nsIXBLBindingAttachedHandler_h__
+
+#include "nsISupports.h"
+
+// {861E971F-D48F-4889-91CD-2A711FA4FDBA}
+#define NS_IXBLBINDINGATTACHEDHANDLER_IID \
+{ 0x861e971f, 0xd48f, 0x4889, { 0x91, 0xcd, 0x2a, 0x71, 0x1f, 0xa4, 0xfd, 0xba } }
+
+class nsIXBLBindingAttachedHandler : public nsISupports
+{
+public:
+  static const nsIID& GetIID() { static nsIID iid = NS_IXBLBINDINGATTACHEDHANDLER_IID; return iid; }
+
+  NS_IMETHOD OnBindingAttached()=0;
+};
+
+#endif // nsIXBLBindingAttachedHandler_h__
diff --git a/layout/xbl/public/nsIXBLBindingAttachedHandler.h b/layout/xbl/public/nsIXBLBindingAttachedHandler.h
new file mode 100644
index 000000000000..666f614018d9
--- /dev/null
+++ b/layout/xbl/public/nsIXBLBindingAttachedHandler.h
@@ -0,0 +1,48 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ *
+ * The contents of this file are subject to the Netscape Public
+ * License Version 1.1 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of
+ * the License at http://www.mozilla.org/NPL/
+ *
+ * Software distributed under the License is distributed on an "AS
+ * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * rights and limitations under the License.
+ *
+ * The Original Code is Mozilla Communicator client code.
+ *
+ * The Initial Developer of the Original Code is Netscape Communications
+ * Corporation.  Portions created by Netscape are
+ * Copyright (C) 1998 Netscape Communications Corporation. All
+ * Rights Reserved.
+ *
+ * Original Author: David W. Hyatt (hyatt@netscape.com)
+ *
+ * Contributor(s): 
+ */
+
+/*
+
+  Private interface to the XBL Binding Attached handler
+
+*/
+
+#ifndef nsIXBLBindingAttachedHandler_h__
+#define nsIXBLBindingAttachedHandler_h__
+
+#include "nsISupports.h"
+
+// {861E971F-D48F-4889-91CD-2A711FA4FDBA}
+#define NS_IXBLBINDINGATTACHEDHANDLER_IID \
+{ 0x861e971f, 0xd48f, 0x4889, { 0x91, 0xcd, 0x2a, 0x71, 0x1f, 0xa4, 0xfd, 0xba } }
+
+class nsIXBLBindingAttachedHandler : public nsISupports
+{
+public:
+  static const nsIID& GetIID() { static nsIID iid = NS_IXBLBINDINGATTACHEDHANDLER_IID; return iid; }
+
+  NS_IMETHOD OnBindingAttached()=0;
+};
+
+#endif // nsIXBLBindingAttachedHandler_h__