diff --git a/themes/default/common.js b/themes/default/common.js
index adc6d6ed06c9cfb7b5cba88f89ab796bfe39f651..a2ade4c8461302ca929846392715e1f1d0ef70f7 100644
--- a/themes/default/common.js
+++ b/themes/default/common.js
@@ -380,6 +380,9 @@ var piwikHelper = {
      */
     getApiFormatTextarea: function (textareaContent)
     {
+        if(typeof textareaContent == 'undefined') {
+            return '';
+        }
         return textareaContent.trim().split("\n").join(',');
     }