diff --git a/reactos/ntoskrnl/ob/obname.c b/reactos/ntoskrnl/ob/obname.c
index 6d0efd32695..f3a91e63dda 100644
--- a/reactos/ntoskrnl/ob/obname.c
+++ b/reactos/ntoskrnl/ob/obname.c
@@ -1126,8 +1126,11 @@ ObQueryNameString(IN PVOID Object,
             else
             {
                 /* Directory without a name, we add "..." */
-                ObjectName -= sizeof(L"...");
-                ObjectName = L"...";
+                ObjectName = (PWCH)((ULONG_PTR)ObjectName -
+                                     sizeof(L"...") + sizeof(UNICODE_NULL));
+                RtlCopyMemory(ObjectName,
+                              L"...",
+                              sizeof(L"...") + sizeof(UNICODE_NULL));
                 break;
             }
         }