diff --git a/lib/trans-sender.js b/lib/trans-sender.js
index 76d56f94..f213d41e 100644
--- a/lib/trans-sender.js
+++ b/lib/trans-sender.js
@@ -104,7 +104,7 @@ var jsonPGenericSender = function(url, payload, callback) {
                        iframe.parentNode.removeChild(iframe);
                        iframe = null;
                    });
-        area.value = null;
+        area.value = '';
         callback();
     };
     iframe.onerror = iframe.onload = completed;