diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index f28dd1e49a82..ebcf8238c616 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -2999,7 +2999,7 @@ def warn_comparison_of_mixed_enum_types : Warning<
   InGroup<DiagGroup<"enum-compare">>;
 def warn_null_in_arithmetic_operation : Warning<
   "use of NULL in arithmetic operation">,
-  InGroup<DiagGroup<"null-arithmetic">>, DefaultIgnore;
+  InGroup<DiagGroup<"null-arithmetic">>;
 
 def err_invalid_this_use : Error<
   "invalid use of 'this' outside of a nonstatic member function">;