diff --git a/classes/Middleware/CspMiddleware.php b/classes/Middleware/CspMiddleware.php
index d5f24f0..8e6ad73 100644
--- a/classes/Middleware/CspMiddleware.php
+++ b/classes/Middleware/CspMiddleware.php
@@ -41,6 +41,7 @@ class CspMiddleware
             ->addDirective('font-src', ['self' => true])
             ->addDirective('style-src', ['self' => true])
             ->addDirective('form-action', ['self' => true])
+            ->addDirective('manifest-src', ['self' => true])
             ->addDirective('base-uri', [])
             ->addDirective('frame-ancestors', [])
             ->addSource('img-src', '*');