diff --git a/config/application.rb b/config/application.rb
index df8269218..de7727cc0 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -65,5 +65,9 @@ module Zammad
 
     # Use a different cache store in production
     config.cache_store = :file_store, 'tmp/cache/file_store'
+
+    # Enable threaded mode
+    config.threadsafe!
+
   end
 end