diff --git a/clang/include/clang/Basic/DiagnosticLexKinds.td b/clang/include/clang/Basic/DiagnosticLexKinds.td
index 65f9f77af49c..13c6911b5534 100644
--- a/clang/include/clang/Basic/DiagnosticLexKinds.td
+++ b/clang/include/clang/Basic/DiagnosticLexKinds.td
@@ -290,8 +290,9 @@ def note_pp_ambiguous_macro_chosen : Note<
   "expanding this definition of %0">;
 def note_pp_ambiguous_macro_other : Note<
   "other definition of %0">;
+// FIXME: Remove DefaultIgnore after reducing noise level.
 def warn_pp_macro_hides_keyword : Extension<
-  "keyword is hidden by macro definition">, InGroup<KeywordAsMacro>;
+  "keyword is hidden by macro definition">, InGroup<KeywordAsMacro>, DefaultIgnore;
 
 def pp_invalid_string_literal : Warning<
   "invalid string literal, ignoring final '\\'">;