diff --git a/workflow/engine/methods/users/usersAjax.php b/workflow/engine/methods/users/usersAjax.php
index b7f657939..0c260fac6 100644
--- a/workflow/engine/methods/users/usersAjax.php
+++ b/workflow/engine/methods/users/usersAjax.php
@@ -13,7 +13,7 @@ if (isset($_SESSION['USR_USERNAME'])) {
 }
 
 // Initializing variables
-$action = $_POST['action'];
+$action = !empty($_POST['action']) ? $_POST['action'] : '';
 $result = new StdClass();
 
 // Try to execute the requested action