diff --git a/lib/public/AppFramework/Http/NotFoundResponse.php b/lib/public/AppFramework/Http/NotFoundResponse.php
index 6d764ec526..2ae3c41fe4 100644
--- a/lib/public/AppFramework/Http/NotFoundResponse.php
+++ b/lib/public/AppFramework/Http/NotFoundResponse.php
@@ -37,6 +37,7 @@ class NotFoundResponse extends Response {
 	public function __construct() {
 		parent::__construct();
 
+		$this->setContentSecurityPolicy(new ContentSecurityPolicy());
 		$this->setStatus(404);
 	}