diff --git a/config/initializers/30-redmine.rb b/config/initializers/30-redmine.rb
index b0cc1f752..f0fc4d4c6 100644
--- a/config/initializers/30-redmine.rb
+++ b/config/initializers/30-redmine.rb
@@ -20,3 +20,9 @@ Redmine::Plugin.load
 unless Redmine::Configuration['mirror_plugins_assets_on_startup'] == false
   Redmine::Plugin.mirror_assets
 end
+
+Rails.application.config.to_prepare do
+  Redmine::FieldFormat::RecordList.subclasses.each do |klass|
+    klass.instance.reset_target_class
+  end
+end
\ No newline at end of file
diff --git a/lib/redmine/field_format.rb b/lib/redmine/field_format.rb
index b71a79f9b..18e5d74a8 100644
--- a/lib/redmine/field_format.rb
+++ b/lib/redmine/field_format.rb
@@ -597,6 +597,10 @@ module Redmine
       def target_class
         @target_class ||= self.class.name[/^(.*::)?(.+)Format$/, 2].constantize rescue nil
       end
+
+      def reset_target_class
+        @target_class = nil
+      end
  
       def possible_custom_value_options(custom_value)
         options = possible_values_options(custom_value.custom_field, custom_value.customized)