diff --git a/dll/win32/netcfgx/precomp.h b/dll/win32/netcfgx/precomp.h
index c461c4d1b33..656b18c1335 100644
--- a/dll/win32/netcfgx/precomp.h
+++ b/dll/win32/netcfgx/precomp.h
@@ -24,6 +24,8 @@
 #include <commctrl.h>
 #include <cfgmgr32.h>
 
+#include <netcfgx_undoc.h>
+
 #include <wine/debug.h>
 
 #include "resource.h"
diff --git a/sdk/include/reactos/netcfgx_undoc.h b/sdk/include/reactos/netcfgx_undoc.h
new file mode 100644
index 00000000000..32ff6f7110e
--- /dev/null
+++ b/sdk/include/reactos/netcfgx_undoc.h
@@ -0,0 +1,27 @@
+#ifndef __NETCFGX_UNDOC_H__
+#define __NETCFGX_UNDOC_H__
+
+#undef  INTERFACE
+#define INTERFACE INetCfgComponentPrivate
+DECLARE_INTERFACE_(INetCfgComponentPrivate, IUnknown)
+{
+    STDMETHOD_(HRESULT,QueryInterface)(THIS_ REFIID riid, void **ppv) PURE;
+    STDMETHOD_(ULONG,AddRef)(THIS)  PURE;
+    STDMETHOD_(ULONG,Release) (THIS) PURE;
+    STDMETHOD_(HRESULT,Unknown1)(THIS_ DWORD dwParam1, DWORD dwParam2) PURE;
+    /* ??? */
+};
+#undef INTERFACE
+
+EXTERN_C const IID IID_INetCfgComponentPrivate;
+
+#if !defined(__cplusplus) || defined(CINTERFACE)
+/*** IUnknown methods ***/
+#define INetCfgComponentPrivate_QueryInterface(p,a,b) (p)->lpVtbl->QueryInterface(p,a,b)
+#define INetCfgComponentPrivate_AddRef(p)             (p)->lpVtbl->AddRef(p)
+#define INetCfgComponentPrivate_Release(p)            (p)->lpVtbl->Release(p)
+#define INetCfgComponentPrivate_Unknown1(p,a,b)       (p)->lpVtbl->Unknown1(p,a,b)
+/* ??? */
+#endif
+
+#endif /* __NETCFGX_UNDOC_H__ */