diff --git a/dlls/uiautomationcore/Makefile.in b/dlls/uiautomationcore/Makefile.in
index 71ea7b99c94..5a72ea144c4 100644
--- a/dlls/uiautomationcore/Makefile.in
+++ b/dlls/uiautomationcore/Makefile.in
@@ -1,5 +1,6 @@
 MODULE = uiautomationcore.dll
 IMPORTLIB = uiautomationcore
+IMPORTS   = uuid ole32
 
 EXTRADLLFLAGS = -Wb,--prefer-native
 
diff --git a/dlls/uiautomationcore/uia_main.c b/dlls/uiautomationcore/uia_main.c
index 2dada95af80..77cacb7c4a4 100644
--- a/dlls/uiautomationcore/uia_main.c
+++ b/dlls/uiautomationcore/uia_main.c
@@ -16,12 +16,134 @@
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  */
 
+#define COBJMACROS
+
 #include "uiautomation.h"
 
 #include "wine/debug.h"
+#include "wine/heap.h"
 
 WINE_DEFAULT_DEBUG_CHANNEL(uiautomation);
 
+struct uia_object_wrapper
+{
+    IUnknown IUnknown_iface;
+    LONG refcount;
+
+    IUnknown *marshaler;
+    IUnknown *marshal_object;
+};
+
+static struct uia_object_wrapper *impl_uia_object_wrapper_from_IUnknown(IUnknown *iface)
+{
+    return CONTAINING_RECORD(iface, struct uia_object_wrapper, IUnknown_iface);
+}
+
+static HRESULT WINAPI uia_object_wrapper_QueryInterface(IUnknown *iface,
+        REFIID riid, void **ppv)
+{
+    struct uia_object_wrapper *wrapper = impl_uia_object_wrapper_from_IUnknown(iface);
+    return IUnknown_QueryInterface(wrapper->marshal_object, riid, ppv);
+}
+
+static ULONG WINAPI uia_object_wrapper_AddRef(IUnknown *iface)
+{
+    struct uia_object_wrapper *wrapper = impl_uia_object_wrapper_from_IUnknown(iface);
+    ULONG refcount = InterlockedIncrement(&wrapper->refcount);
+
+    TRACE("%p, refcount %d\n", iface, refcount);
+
+    return refcount;
+}
+
+static ULONG WINAPI uia_object_wrapper_Release(IUnknown *iface)
+{
+    struct uia_object_wrapper *wrapper = impl_uia_object_wrapper_from_IUnknown(iface);
+    ULONG refcount = InterlockedDecrement(&wrapper->refcount);
+
+    TRACE("%p, refcount %d\n", iface, refcount);
+    if (!refcount)
+    {
+        IUnknown_Release(wrapper->marshaler);
+        heap_free(wrapper);
+    }
+
+    return refcount;
+}
+
+static const IUnknownVtbl uia_object_wrapper_vtbl = {
+    uia_object_wrapper_QueryInterface,
+    uia_object_wrapper_AddRef,
+    uia_object_wrapper_Release,
+};
+
+/*
+ * When passing the ReservedNotSupportedValue/ReservedMixedAttributeValue
+ * interface pointers across apartments within the same process, create a free
+ * threaded marshaler so that the pointer value is preserved.
+ */
+static HRESULT create_uia_object_wrapper(IUnknown *reserved, void **ppv)
+{
+    struct uia_object_wrapper *wrapper;
+    HRESULT hr;
+
+    TRACE("%p, %p\n", reserved, ppv);
+
+    wrapper = heap_alloc(sizeof(*wrapper));
+    if (!wrapper)
+        return E_OUTOFMEMORY;
+
+    wrapper->IUnknown_iface.lpVtbl = &uia_object_wrapper_vtbl;
+    wrapper->marshal_object = reserved;
+    wrapper->refcount = 1;
+
+    if (FAILED(hr = CoCreateFreeThreadedMarshaler(&wrapper->IUnknown_iface, &wrapper->marshaler)))
+    {
+        heap_free(wrapper);
+        return hr;
+    }
+
+    hr = IUnknown_QueryInterface(wrapper->marshaler, &IID_IMarshal, ppv);
+    IUnknown_Release(&wrapper->IUnknown_iface);
+
+    return hr;
+}
+
+/*
+ * UiaReservedNotSupportedValue object.
+ */
+static HRESULT WINAPI uia_reserved_obj_QueryInterface(IUnknown *iface,
+        REFIID riid, void **ppv)
+{
+    *ppv = NULL;
+    if (IsEqualIID(riid, &IID_IUnknown))
+        *ppv = iface;
+    else if (IsEqualIID(riid, &IID_IMarshal))
+        return create_uia_object_wrapper(iface, ppv);
+    else
+        return E_NOINTERFACE;
+
+    return S_OK;
+}
+
+static ULONG WINAPI uia_reserved_obj_AddRef(IUnknown *iface)
+{
+    return 1;
+}
+
+static ULONG WINAPI uia_reserved_obj_Release(IUnknown *iface)
+{
+    return 1;
+}
+
+static const IUnknownVtbl uia_reserved_obj_vtbl = {
+    uia_reserved_obj_QueryInterface,
+    uia_reserved_obj_AddRef,
+    uia_reserved_obj_Release,
+};
+
+static IUnknown uia_reserved_ns_iface = {&uia_reserved_obj_vtbl};
+
 /***********************************************************************
  *          UiaClientsAreListening (uiautomationcore.@)
  */
@@ -46,8 +168,13 @@ HRESULT WINAPI UiaGetReservedMixedAttributeValue(IUnknown **value)
  */
 HRESULT WINAPI UiaGetReservedNotSupportedValue(IUnknown **value)
 {
-    FIXME("(%p) stub!\n", value);
-    *value = NULL;
+    TRACE("(%p)\n", value);
+
+    if (!value)
+        return E_INVALIDARG;
+
+    *value = &uia_reserved_ns_iface;
+
     return S_OK;
 }