diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index 2bbc376..bcf4774 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -1624,8 +1624,7 @@
 def warn_printf_missing_format_string : Warning<
   "format string missing">, InGroup<Format>;
 def warn_null_arg : Warning<
-  "argument is null where non-null is required">,
-  InGroup<NonNull>, DefaultIgnore;
+  "argument is null where non-null is required">, InGroup<NonNull>;
 def warn_printf_empty_format_string : Warning<
   "format string is empty">, InGroup<FormatZeroLength>;
 def warn_printf_format_string_is_wide_literal : Warning<