diff --git a/lib/IHP/static/helpers.js b/lib/IHP/static/helpers.js
index 039cea78a..633d181a5 100644
--- a/lib/IHP/static/helpers.js
+++ b/lib/IHP/static/helpers.js
@@ -296,7 +296,15 @@ window.submitForm = function (form, possibleClickedButton) {
             'Content-Type',
             'application/x-www-form-urlencoded'
         );
-        request.send(parameters.join('&'));
+
+        try {
+            request.send(parameters.join('&'));
+        } catch (e) {
+            // If the send method throws an exception, redirect to the form action URL.
+            // This can happen for example if redirecting to an external site, which doesn't have CORS enabled,
+            // so we can't use Ajax.
+            window.location.href = url;
+        }
     }
 
     var buttons = form.getElementsByTagName('button');