diff --git a/dlls/rpcrt4/tests/ndr_marshall.c b/dlls/rpcrt4/tests/ndr_marshall.c
index c625e26d5dc..4a5566f0a37 100644
--- a/dlls/rpcrt4/tests/ndr_marshall.c
+++ b/dlls/rpcrt4/tests/ndr_marshall.c
@@ -20,6 +20,9 @@
 
 #include <stdarg.h>
 
+#define NTDDI_WIN2K   0x05000000
+#define NTDDI_VERSION NTDDI_WIN2K /* for some MIDL_STUB_MESSAGE fields */
+
 #include "wine/test.h"
 #include <windef.h>
 #include <winbase.h>
@@ -892,8 +895,8 @@ static void test_client_init(void)
     TEST_POINTER_UNSET(VarianceMark);
     ok(stubMsg.Unused == 0xcccccccc, "Unused should have be unset instead of 0x%x\n", stubMsg.Unused);
     TEST_POINTER_UNSET(pContext);
-    TEST_ULONG_UNSET(Reserved51_1);
-    TEST_ULONG_UNSET(Reserved51_2);
+    TEST_POINTER_UNSET(ContextHandleHash);
+    TEST_POINTER_UNSET(pUserMarshalList);
     TEST_ULONG_UNSET(Reserved51_3);
     TEST_ULONG_UNSET(Reserved51_4);
     TEST_ULONG_UNSET(Reserved51_5);
diff --git a/include/rpcndr.h b/include/rpcndr.h
index 01beba272b6..126091bae89 100644
--- a/include/rpcndr.h
+++ b/include/rpcndr.h
@@ -222,10 +222,10 @@ typedef struct _MIDL_STUB_MESSAGE
   CS_STUB_INFO *pCSInfo;
   unsigned char *ConformanceMark;
   unsigned char *VarianceMark;
-  INT_PTR Unused;
+  INT_PTR Unused; /* BackingStoreLowMark on IA64 */
   struct _NDR_PROC_CONTEXT *pContext;
-  INT_PTR Reserved51_1;
-  INT_PTR Reserved51_2;
+  void* ContextHandleHash;
+  void* pUserMarshalList;
   INT_PTR Reserved51_3;
   INT_PTR Reserved51_4;
   INT_PTR Reserved51_5;