diff --git a/src/app/code/community/Zendesk/Zendesk/controllers/ApiController.php b/src/app/code/community/Zendesk/Zendesk/controllers/ApiController.php
index 54dc0e1..b19f4ef 100644
--- a/src/app/code/community/Zendesk/Zendesk/controllers/ApiController.php
+++ b/src/app/code/community/Zendesk/Zendesk/controllers/ApiController.php
@@ -445,6 +445,7 @@ public function searchCustomersAction()
 
         $filters = json_decode($req->getRawBody());
         $genericFilters = array();
+        $productFilters = null;
 
         foreach($filters as $key => $val) {
             if($key == $customerKey) {