diff --git a/config/application.rb b/config/application.rb
index bdcb544d9b4730524b060b00cdac1f06f3ab64ec..18d5b0597644ec5ff85d55c729276040e28cb9f0 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -655,7 +655,8 @@ class Application < Rails::Application
         ActiveSupport::TimeWithZone,
         ActiveSupport::TimeZone,
         Gitlab::Color, # https://gitlab.com/gitlab-org/gitlab/-/issues/368844,
-        Hashie::Array # https://gitlab.com/gitlab-org/gitlab/-/issues/378089
+        Hashie::Array, # https://gitlab.com/gitlab-org/gitlab/-/issues/378089
+        Hashie::Mash # https://gitlab.com/gitlab-org/gitlab/-/issues/440316
       ]
       #
       # Restore setting the YAML permitted classes for ActiveRecord