diff --git a/sdk/include/psdk/winbase.h b/sdk/include/psdk/winbase.h
index 445c255b0ea..b6bda981368 100644
--- a/sdk/include/psdk/winbase.h
+++ b/sdk/include/psdk/winbase.h
@@ -354,7 +354,9 @@ extern "C" {
 #define LOAD_LIBRARY_SAFE_CURRENT_DIRS              0x00002000
 #define LOAD_LIBRARY_SEARCH_SYSTEM32_NO_FORWARDER   0x00004000
 #else // NTDDI_WIN10_RS1
+#if (_WIN32_WINNT >= _WIN32_WINNT_VISTA)
 #define LOAD_LIBRARY_SEARCH_SYSTEM32_NO_FORWARDER   LOAD_LIBRARY_SEARCH_SYSTEM32
+#endif // _WIN32_WINNT_VISTA
 #endif // NTDDI_WIN10_RS1
 #if (NTDDI_VERSION >= NTDDI_WIN10_RS2)
 #define LOAD_LIBRARY_OS_INTEGRITY_CONTINUITY        0x00008000