diff --git a/include/mshtmhst.idl b/include/mshtmhst.idl
index 57e2eaddec5..1ed8b90b02d 100644
--- a/include/mshtmhst.idl
+++ b/include/mshtmhst.idl
@@ -48,6 +48,11 @@ cpp_quote("#define HTMLDLG_VERIFY          0x0100")
 cpp_quote("#define PRINT_DONTBOTHERUSER     0x0001")
 cpp_quote("#define PRINT_WAITFORCOMPLETION  0x0002")
 
+cpp_quote("#ifndef __IHTMLWindow2_FWD_DEFINED__")
+cpp_quote("#define __IHTMLWindow2_FWD_DEFINED__")
+cpp_quote("typedef interface IHTMLWindow2 IHTMLWindow2;")
+cpp_quote("#endif")
+
 /*****************************************************************************
  *    IHostDialogHelper interface
  */