diff --git a/MdePkg/Include/Protocol/Http.h b/MdePkg/Include/Protocol/Http.h
index 28e6221593..7d9481a2e6 100644
--- a/MdePkg/Include/Protocol/Http.h
+++ b/MdePkg/Include/Protocol/Http.h
@@ -98,7 +98,8 @@ typedef enum {
   HTTP_STATUS_503_SERVICE_UNAVAILABLE,
   HTTP_STATUS_504_GATEWAY_TIME_OUT,
   HTTP_STATUS_505_HTTP_VERSION_NOT_SUPPORTED,
-  HTTP_STATUS_308_PERMANENT_REDIRECT
+  HTTP_STATUS_308_PERMANENT_REDIRECT,
+  HTTP_STATUS_429_TOO_MANY_REQUESTS
 } EFI_HTTP_STATUS_CODE;
 
 ///