diff --git a/src/applications/files/controller/PhabricatorFileLightboxController.php b/src/applications/files/controller/PhabricatorFileLightboxController.php
index e57d977786..11d4b95bc1 100644
--- a/src/applications/files/controller/PhabricatorFileLightboxController.php
+++ b/src/applications/files/controller/PhabricatorFileLightboxController.php
@@ -1,105 +1,109 @@
 <?php
 
 final class PhabricatorFileLightboxController
   extends PhabricatorFileController {
 
+  public function shouldAllowPublic() {
+    return true;
+  }
+
   public function handleRequest(AphrontRequest $request) {
     $viewer = $request->getViewer();
     $phid = $request->getURIData('phid');
     $comment = $request->getStr('comment');
 
     $file = id(new PhabricatorFileQuery())
       ->setViewer($viewer)
       ->withPHIDs(array($phid))
       ->executeOne();
     if (!$file) {
       return new Aphront404Response();
     }
 
     if (strlen($comment)) {
       $xactions = array();
       $xactions[] = id(new PhabricatorFileTransaction())
         ->setTransactionType(PhabricatorTransactions::TYPE_COMMENT)
         ->attachComment(
           id(new PhabricatorFileTransactionComment())
             ->setContent($comment));
 
       $editor = id(new PhabricatorFileEditor())
         ->setActor($viewer)
         ->setContinueOnNoEffect(true)
         ->setContentSourceFromRequest($request);
 
       $editor->applyTransactions($file, $xactions);
     }
 
     $transactions = id(new PhabricatorFileTransactionQuery())
       ->withTransactionTypes(array(PhabricatorTransactions::TYPE_COMMENT));
     $timeline = $this->buildTransactionTimeline($file, $transactions);
 
     $comment_form = $this->renderCommentForm($file);
 
     $info = phutil_tag(
       'div',
       array(
         'class' => 'phui-comment-panel-header',
       ),
       $file->getName());
 
     require_celerity_resource('phui-comment-panel-css');
     $content = phutil_tag(
       'div',
       array(
         'class' => 'phui-comment-panel',
       ),
       array(
         $info,
         $timeline,
         $comment_form,
       ));
 
     return id(new AphrontAjaxResponse())
       ->setContent($content);
   }
 
   private function renderCommentForm(PhabricatorFile $file) {
     $viewer = $this->getViewer();
 
     if (!$viewer->isLoggedIn()) {
       $login_href = id(new PhutilURI('/auth/start/'))
         ->setQueryParam('next', '/'.$file->getMonogram());
       return id(new PHUIFormLayoutView())
         ->addClass('phui-comment-panel-empty')
         ->appendChild(
           id(new PHUIButtonView())
           ->setTag('a')
           ->setText(pht('Login to Comment'))
           ->setHref((string)$login_href));
     }
 
     $draft = PhabricatorDraft::newFromUserAndKey(
       $viewer,
       $file->getPHID());
     $post_uri = $this->getApplicationURI('thread/'.$file->getPHID().'/');
 
     $form = id(new AphrontFormView())
       ->setUser($viewer)
       ->setAction($post_uri)
       ->addSigil('lightbox-comment-form')
       ->addClass('lightbox-comment-form')
       ->setWorkflow(true)
       ->appendChild(
         id(new PhabricatorRemarkupControl())
         ->setUser($viewer)
         ->setName('comment')
         ->setValue($draft->getDraft()))
       ->appendChild(
         id(new AphrontFormSubmitControl())
           ->setValue(pht('Comment')));
 
     $view = phutil_tag_div('phui-comment-panel', $form);
 
     return $view;
 
   }
 
 }