diff --git a/app/call_block/call_block.php b/app/call_block/call_block.php
index a777108bfb..31fd2c80d6 100644
--- a/app/call_block/call_block.php
+++ b/app/call_block/call_block.php
@@ -122,7 +122,7 @@
 //get the list
 	$sql = "select * from view_call_block ";
 	$sql .= "where domain_uuid = :domain_uuid ";
-	if (!permission_exists('call_block_all') && is_array($_SESSION['user']['extension'] && count($_SESSION['user']['extension']) > 0)) {
+	if (!permission_exists('call_block_all') && is_array($_SESSION['user']['extension']) && count($_SESSION['user']['extension']) > 0) {
 		$sql .= "and extension_uuid in (";
 		$x = 0;
 		foreach ($_SESSION['user']['extension'] as $field) {