diff --git a/extension/lite/product/ext/model/getpairs.php b/extension/lite/product/ext/model/getpairs.php
index d09219a3e2..4240902fad 100644
--- a/extension/lite/product/ext/model/getpairs.php
+++ b/extension/lite/product/ext/model/getpairs.php
@@ -6,7 +6,7 @@
  * @param  string $programID
  * @return array
  */
-public function getPairs($mode = '', $programID = 0)
+public function getPairs($mode = '', $programID = 0, $append = '')
 {
     if(defined('TUTORIAL')) return $this->loadModel('tutorial')->getProductPairs();