diff --git a/include/clang/Driver/CLCompatOptions.td b/include/clang/Driver/CLCompatOptions.td
index a35852dbf9d4b55d7a4b0b5027c4d9fa3176fce2..c1f0a89b5dc8ff150a377b97bf7daf278aae7326 100644
--- a/include/clang/Driver/CLCompatOptions.td
+++ b/include/clang/Driver/CLCompatOptions.td
@@ -154,6 +154,8 @@ def _SLASH_WX_ : CLFlag<"WX-">, HelpText<"Do not treat warnings as errors">,
 def _SLASH_w_flag : CLFlag<"w">, HelpText<"Disable all warnings">, Alias<w>;
 def _SLASH_wd4005 : CLFlag<"wd4005">, Alias<W_Joined>,
   AliasArgs<["no-macro-redefined"]>;
+def _SLASH_wd4018 : CLFlag<"wd4018">, Alias<W_Joined>,
+  AliasArgs<["no-sign-compare"]>;
 def _SLASH_wd4100 : CLFlag<"wd4100">, Alias<W_Joined>,
   AliasArgs<["no-unused-parameter"]>;
 def _SLASH_wd4910 : CLFlag<"wd4910">, Alias<W_Joined>,