diff --git a/plugins/calendar/calendar_ui.js b/plugins/calendar/calendar_ui.js
index da2c7186..d7ace944 100644
--- a/plugins/calendar/calendar_ui.js
+++ b/plugins/calendar/calendar_ui.js
@@ -1946,9 +1946,9 @@ function rcube_calendar_ui(settings)
         + (!data.noreply && settings.itip_notify & 1 ? 'checked="checked" ' : '') + '/>';
 
       if (data['delegated-to'])
-        tooltip = rcmail.gettext('delegatedto', 'calendar') + data['delegated-to'];
+        tooltip = rcmail.gettext('libcalendaring.delegatedto') + ' ' + data['delegated-to'];
       else if (data['delegated-from'])
-        tooltip = rcmail.gettext('delegatedfrom', 'calendar') + data['delegated-from'];
+        tooltip = rcmail.gettext('libcalendaring.delegatedfrom') + ' ' + data['delegated-from'];
       else if (status)
         tooltip = status_label;
 
diff --git a/plugins/calendar/localization/en_US.inc b/plugins/calendar/localization/en_US.inc
index 43d07922..1ca5c632 100644
--- a/plugins/calendar/localization/en_US.inc
+++ b/plugins/calendar/localization/en_US.inc
@@ -164,8 +164,6 @@ $labels['availbusy'] = 'Busy';
 $labels['availunknown'] = 'Unknown';
 $labels['availtentative'] = 'Tentative';
 $labels['availoutofoffice'] = 'Out of Office';
-$labels['delegatedto'] = 'Delegated to: ';
-$labels['delegatedfrom'] = 'Delegated from: ';
 $labels['scheduletime'] = 'Find availability';
 $labels['sendinvitations'] = 'Send invitations';
 $labels['sendnotifications'] = 'Notify participants about modifications';
diff --git a/plugins/libcalendaring/libcalendaring.js b/plugins/libcalendaring/libcalendaring.js
index d9f24751..2836986b 100644
--- a/plugins/libcalendaring/libcalendaring.js
+++ b/plugins/libcalendaring/libcalendaring.js
@@ -1026,9 +1026,9 @@ rcube_libcalendaring.attendee_html = function(data)
     }
 
     if (data['delegated-to'])
-        tooltip = rcmail.gettext('delegatedto', context) + data['delegated-to'];
+        tooltip = rcmail.gettext('delegatedto', context) + ' ' + data['delegated-to'];
     else if (data['delegated-from'])
-        tooltip = rcmail.gettext('delegatedfrom', context) + data['delegated-from'];
+        tooltip = rcmail.gettext('delegatedfrom', context) + ' ' + data['delegated-from'];
 
     return $('<span>').append(
             $('<span>').attr({'class': 'attendee ' + status, title: tooltip}).append(name.text(dispname))
diff --git a/plugins/libcalendaring/libcalendaring.php b/plugins/libcalendaring/libcalendaring.php
index 92618b02..df12002a 100644
--- a/plugins/libcalendaring/libcalendaring.php
+++ b/plugins/libcalendaring/libcalendaring.php
@@ -131,12 +131,13 @@ class libcalendaring extends rcube_plugin
             $this->include_script('libcalendaring.js');
             $this->include_stylesheet($this->local_skin_path() . '/libcal.css');
 
-            $this->rc->output->add_label(
-                'libcalendaring.itipaccepted', 'libcalendaring.itiptentative', 'libcalendaring.itipdeclined',
-                'libcalendaring.itipdelegated', 'libcalendaring.expandattendeegroup', 'libcalendaring.expandattendeegroupnodata',
-                'libcalendaring.statusorganizer', 'libcalendaring.statusaccepted', 'libcalendaring.statusdeclined',
-                'libcalendaring.statusdelegated', 'libcalendaring.statusunknown', 'libcalendaring.statusneeds-action',
-                'libcalendaring.statustentative', 'libcalendaring.statuscompleted', 'libcalendaring.statusin-process'
+            $this->add_label(
+                'itipaccepted', 'itiptentative', 'itipdeclined',
+                'itipdelegated', 'expandattendeegroup', 'expandattendeegroupnodata',
+                'statusorganizer', 'statusaccepted', 'statusdeclined',
+                'statusdelegated', 'statusunknown', 'statusneeds-action',
+                'statustentative', 'statuscompleted', 'statusin-process',
+                'delegatedto', 'delegatedfrom'
             );
         }
 
diff --git a/plugins/libcalendaring/localization/de_CH.inc b/plugins/libcalendaring/localization/de_CH.inc
index 4a9b0d8e..c36efbde 100644
--- a/plugins/libcalendaring/localization/de_CH.inc
+++ b/plugins/libcalendaring/localization/de_CH.inc
@@ -85,6 +85,8 @@ $labels['statusneeds-action'] = 'Braucht Aktion';
 $labels['statusunknown'] = 'Unbekannt';
 $labels['statuscompleted'] = 'Abgeschlossen';
 $labels['statusin-process'] = 'In Bearbeitung';
+$labels['delegatedto'] = 'Delegiert an:';
+$labels['delegatedfrom'] = 'Delegiert von:';
 $labels['itipinvitation'] = 'Einladung zu';
 $labels['itipupdate'] = 'Aktialisiert:';
 $labels['itipcancellation'] = 'Abgesagt:';
diff --git a/plugins/libcalendaring/localization/de_DE.inc b/plugins/libcalendaring/localization/de_DE.inc
index b04164eb..9919b583 100644
--- a/plugins/libcalendaring/localization/de_DE.inc
+++ b/plugins/libcalendaring/localization/de_DE.inc
@@ -84,6 +84,8 @@ $labels['statusdelegated'] = 'Delegiert';
 $labels['statusneeds-action'] = 'Braucht Aktion';
 $labels['statusunknown'] = 'Unbekannt';
 $labels['statuscompleted'] = 'Abgeschlossen';
+$labels['delegatedto'] = 'Delegiert an:';
+$labels['delegatedfrom'] = 'Delegiert von:';
 $labels['statusin-process'] = 'In Bearbeitung';
 $labels['itipinvitation'] = 'Einladung zu';
 $labels['itipupdate'] = 'Aktialisiert:';
diff --git a/plugins/libcalendaring/localization/en_US.inc b/plugins/libcalendaring/localization/en_US.inc
index bbdcc2bd..1d871207 100644
--- a/plugins/libcalendaring/localization/en_US.inc
+++ b/plugins/libcalendaring/localization/en_US.inc
@@ -97,6 +97,8 @@ $labels['statusneeds-action'] = 'Needs action';
 $labels['statusunknown'] = 'Unknown';
 $labels['statuscompleted'] = 'Completed';
 $labels['statusin-process'] = 'In process';
+$labels['delegatedto'] = 'Delegated to: ';
+$labels['delegatedfrom'] = 'Delegated from: ';
 
 // itip related labels
 $labels['itipinvitation'] = 'Invitation to';
diff --git a/plugins/tasklist/localization/en_US.inc b/plugins/tasklist/localization/en_US.inc
index e42194c4..d34f17de 100644
--- a/plugins/tasklist/localization/en_US.inc
+++ b/plugins/tasklist/localization/en_US.inc
@@ -197,8 +197,6 @@ $labels['removefromcalendar'] = 'Remove from my tasks';
 $labels['delegateinvitation'] = 'Delegate assignment';
 
 $labels['andnmore'] = '$nr more...';
-$labels['delegatedto'] = 'Delegated to: ';
-$labels['delegatedfrom'] = 'Delegated from: ';
 $labels['savetotasklist'] = 'Save to tasks';
 $labels['comment'] = 'Comment';
 $labels['errorimportingtask'] = 'Failed to import task(s)';
diff --git a/plugins/tasklist/tasklist.js b/plugins/tasklist/tasklist.js
index ca2ceb51..a44ae3d9 100644
--- a/plugins/tasklist/tasklist.js
+++ b/plugins/tasklist/tasklist.js
@@ -1890,9 +1890,9 @@ function rcube_tasklist_ui(settings)
             + (!data.noreply && settings.itip_notify & 1 ? 'checked="checked" ' : '') + '/>';
 
         if (data['delegated-to'])
-            tooltip = rcmail.gettext('delegatedto', 'tasklist') + data['delegated-to'];
+            tooltip = rcmail.gettext('libcalendaring.delegatedto') + ' ' + data['delegated-to'];
         else if (data['delegated-from'])
-            tooltip = rcmail.gettext('delegatedfrom', 'tasklist') + data['delegated-from'];
+            tooltip = rcmail.gettext('libcalendaring.delegatedfrom') + ' ' + data['delegated-from'];
         else if (status)
             tooltip = status_label;