diff --git a/plugins/libcalendaring/libcalendaring.php b/plugins/libcalendaring/libcalendaring.php
index 8a7de9b2..1053f8e9 100644
--- a/plugins/libcalendaring/libcalendaring.php
+++ b/plugins/libcalendaring/libcalendaring.php
@@ -137,7 +137,7 @@ class libcalendaring extends rcube_plugin
                 'statusorganizer', 'statusaccepted', 'statusdeclined',
                 'statusdelegated', 'statusunknown', 'statusneeds-action',
                 'statustentative', 'statuscompleted', 'statusin-process',
-                'delegatedto', 'delegatedfrom'
+                'delegatedto', 'delegatedfrom', 'showmore'
             );
         }