diff --git a/core/modules/image/src/Controller/ImageStyleDownloadController.php b/core/modules/image/src/Controller/ImageStyleDownloadController.php
index d484183..1407298 100644
--- a/core/modules/image/src/Controller/ImageStyleDownloadController.php
+++ b/core/modules/image/src/Controller/ImageStyleDownloadController.php
@@ -180,8 +180,8 @@ public function deliver(Request $request, $scheme, ImageStyleInterface $image_st
       );
       // \Drupal\Core\EventSubscriber\FinishResponseSubscriber::onRespond()
       // sets response as not cacheable if the Cache-Control header is not
-      // already modified. We pass in FALSE for the $public parameter to make
-      // sure we don't change the headers.
+      // already modified. We pass in FALSE for non-private schemes for the
+      // $public parameter to make sure we don't change the headers.
       return new BinaryFileResponse($uri, 200, $headers, $scheme !== 'private');
     }
     else {