diff --git a/app/services/system_hooks_service.rb b/app/services/system_hooks_service.rb
index 41014f199d5..9ac1cfb3ba5 100644
--- a/app/services/system_hooks_service.rb
+++ b/app/services/system_hooks_service.rb
@@ -18,7 +18,7 @@ class SystemHooksService
   def build_event_data(model, event)
     data = {
       event_name: build_event_name(model, event),
-      created_at: model.created_at
+      created_at: model.created_at.xmlschema
     }
 
     case model