diff --git a/setup/inc/header.inc.php b/setup/inc/header.inc.php
index 0bfc0ec85edaa6b44a650a92ca7d00ff3b8d140d..900c143fad2eb91791933b0567fddf63cf03d746 100644
--- a/setup/inc/header.inc.php
+++ b/setup/inc/header.inc.php
@@ -1,5 +1,6 @@
<?php
-header("Content-Security-Policy: frame-ancestors '".$cfg->getAllowIframes()."';");
+if ($cfg)
+ header("Content-Security-Policy: frame-ancestors '".$cfg->getAllowIframes()."';");
?>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">