diff --git a/app/models/observer/ticket/notification.rb b/app/models/observer/ticket/notification.rb
index 1418032b2..f80218257 100644
--- a/app/models/observer/ticket/notification.rb
+++ b/app/models/observer/ticket/notification.rb
@@ -34,6 +34,7 @@ class Observer::Ticket::Notification < ActiveRecord::Observer
         next if !ticket
 
         article = ticket.articles[-1]
+        next if !article
       else
         raise "unknown object for notification #{event[:name]}"
       end
@@ -237,17 +238,13 @@ class Observer::Ticket::Notification < ActiveRecord::Observer
 
     # add history record
     if recipient_list != ''
-      created_by_id = 1
-      if article && article.created_by_id
-        created_by_id = article.created_by_id
-      end
       History.add(
         :o_id                   => ticket.id,
         :history_type           => 'notification',
         :history_object         => 'Ticket',
         :value_from             => notification_subject,
         :value_to               => recipient_list,
-        :created_by_id          => created_by_id
+        :created_by_id          => article.created_by_id || 1
       )
     end
   end