diff --git a/plugins/calendar/calendar_ui.js b/plugins/calendar/calendar_ui.js
index 000cc3cd..64210f89 100644
--- a/plugins/calendar/calendar_ui.js
+++ b/plugins/calendar/calendar_ui.js
@@ -450,8 +450,9 @@ function rcube_calendar_ui(settings)
         if (typeof event.alarms == 'string')
           event.alarms = event.alarms.split(';');
         
-        for (var alarm, i=0; i < event.alarms.length; i++) {
-          alarm = String(event.alarms[i]).split(':');
+        var valarms = event.alarms || [''];
+        for (var alarm, i=0; i < valarms.length; i++) {
+          alarm = String(valarms[i]).split(':');
           if (!alarm[1] && alarm[0]) alarm[1] = 'DISPLAY';
           $('#eventedit select.edit-alarm-type').val(alarm[1]);
           
diff --git a/plugins/tasklist/tasklist.js b/plugins/tasklist/tasklist.js
index 7fa17f67..530bb25d 100644
--- a/plugins/tasklist/tasklist.js
+++ b/plugins/tasklist/tasklist.js
@@ -1011,8 +1011,9 @@ function rcube_tasklist_ui(settings)
             if (typeof rec.alarms == 'string')
                 rec.alarms = rec.alarms.split(';');
 
-          for (var alarm, i=0; i < rec.alarms.length; i++) {
-              alarm = String(rec.alarms[i]).split(':');
+          var valarms = rec.alarms || [''];
+          for (var alarm, i=0; i < valarms.length; i++) {
+              alarm = String(valarms[i]).split(':');
               if (!alarm[1] && alarm[0]) alarm[1] = 'DISPLAY';
               $('#taskedit select.edit-alarm-type').val(alarm[1]);