diff --git a/paypal_payment_pps/paypal_payment_pps.api.php b/paypal_payment_pps/paypal_payment_pps.api.php
new file mode 100644
index 0000000..9887c09
--- /dev/null
+++ b/paypal_payment_pps/paypal_payment_pps.api.php
@@ -0,0 +1,20 @@
+<?php
+
+/**
+ * @file
+ * Contains hook documentation.
+ */
+
+/**
+ * Alters redirect data.
+ *
+ * @param Payment $payment
+ *   The payment for which to alter the data.
+ * @param array $data
+ *   The data to alter. Keys and values correspond to Paypal PPS's documented
+ *   redirect data.
+ */
+function hook_paypal_payment_pps_data(Payment $payment, array &$data) {
+  // Enforce the interface language to be Ukrainian.
+  $data['lc'] = 'UK';
+}
diff --git a/paypal_payment_pps/paypal_payment_pps.module b/paypal_payment_pps/paypal_payment_pps.module
index 9d1ebd1..2053510 100755
--- a/paypal_payment_pps/paypal_payment_pps.module
+++ b/paypal_payment_pps/paypal_payment_pps.module
@@ -201,6 +201,7 @@ function paypal_payment_pps_form_redirect(array $form, array &$form_state, Payme
   $form['#action'] = url($controller_data['server'], array(
     'external' => TRUE,
   ));
+  drupal_alter('paypal_payment_pps_data', $payment, $data);
   foreach ($data as $name => $value) {
     if (!empty($value)) {
       $form[$name] = array(