diff --git a/config/application.rb b/config/application.rb
index 3b36d7cb7..05160d03e 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -37,8 +37,7 @@ module RedmineApp
     # config.plugins = [ :exception_notification, :ssl_requirement, :all ]
 
     # Activate observers that should always be running.
-    config.active_record.observers = :journals_for_message_observer, :message_observer, :issue_observer, :journal_observer, :news_observer,
-        :document_observer, :wiki_content_observer, :comment_observer, :forum_observer, :memo_observer
+    config.active_record.observers = :journals_for_message_observer, :issue_observer, :journal_observer, :wiki_content_observer
 
     config.active_record.store_full_sti_class = true
     config.active_record.default_timezone = :local