diff --git a/commerce_cardonfile.module b/commerce_cardonfile.module
index c1e1ce4..bc2a73d 100644
--- a/commerce_cardonfile.module
+++ b/commerce_cardonfile.module
@@ -708,7 +708,7 @@ function commerce_cardonfile_commerce_checkout_form_submit($form, &$form_state)
  * enabled payment methods.
  */
 function commerce_cardonfile_form_commerce_payment_order_transaction_add_form_alter(&$form, &$form_state) {
-  $payment_method = $form_state['payment_method'];
+  $payment_method = isset($form_state['payment_method']) ? $form_state['payment_method']:null;
   $form['payment_terminal']['#prefix'] = '<div id="payment-terminal-ajax-wrapper">';
   $form['payment_terminal']['#suffix'] = '</div>';