diff --git a/modules/monitoring/library/Monitoring/Object/Host.php b/modules/monitoring/library/Monitoring/Object/Host.php
index 8a8c032b5..6fe058972 100644
--- a/modules/monitoring/library/Monitoring/Object/Host.php
+++ b/modules/monitoring/library/Monitoring/Object/Host.php
@@ -93,6 +93,7 @@ class Host extends MonitoredObject
             'host_icon_image',
             'host_icon_image_alt',
             'host_acknowledged',
+            'host_acknowledgement_type',
             'host_action_url',
             'host_active_checks_enabled',
             'host_active_checks_enabled_changed',