diff --git a/src/applications/diffusion/controller/DiffusionBrowseController.php b/src/applications/diffusion/controller/DiffusionBrowseController.php
index 33fc2e2d15..b75e465776 100644
--- a/src/applications/diffusion/controller/DiffusionBrowseController.php
+++ b/src/applications/diffusion/controller/DiffusionBrowseController.php
@@ -1,215 +1,218 @@
 <?php
 
 abstract class DiffusionBrowseController extends DiffusionController {
 
   public function shouldAllowPublic() {
     return true;
   }
 
   protected function renderSearchForm($collapsed) {
     $drequest = $this->getDiffusionRequest();
     $form = id(new AphrontFormView())
       ->setUser($this->getRequest()->getUser())
       ->setMethod('GET');
 
     switch ($drequest->getRepository()->getVersionControlSystem()) {
       case PhabricatorRepositoryType::REPOSITORY_TYPE_SVN:
         $form->appendChild(pht('Search is not available in Subversion.'));
         break;
 
       default:
         $form
           ->appendChild(
             id(new AphrontFormTextControl())
               ->setLabel(pht('Search Here'))
               ->setName('grep')
               ->setValue($this->getRequest()->getStr('grep'))
               ->setCaption(pht('Enter a regular expression.')))
           ->appendChild(
             id(new AphrontFormSubmitControl())
               ->setValue(pht('Search File Content')));
         break;
     }
 
     $filter = new AphrontListFilterView();
     $filter->appendChild($form);
 
     if ($collapsed) {
       $filter->setCollapsed(
         pht('Show Search'),
         pht('Hide Search'),
         pht('Search for file content in this directory.'),
         '#');
     }
 
     return $filter;
   }
 
   protected function markupText($text) {
     $engine = PhabricatorMarkupEngine::newDiffusionMarkupEngine();
     $engine->setConfig('viewer', $this->getRequest()->getUser());
     $text = $engine->markupText($text);
 
     $text = phutil_tag(
       'div',
       array(
         'class' => 'phabricator-remarkup',
       ),
       $text);
 
     return $text;
   }
 
   protected function buildHeaderView(DiffusionRequest $drequest) {
     $viewer = $this->getRequest()->getUser();
 
     $header = id(new PHUIHeaderView())
       ->setUser($viewer)
       ->setHeader($this->renderPathLinks($drequest, $mode = 'browse'))
       ->setPolicyObject($drequest->getRepository());
 
     return $header;
   }
 
   protected function buildActionView(DiffusionRequest $drequest) {
     $viewer = $this->getRequest()->getUser();
 
     $view = id(new PhabricatorActionListView())
       ->setUser($viewer);
 
     $history_uri = $drequest->generateURI(
       array(
         'action' => 'history',
       ));
 
     $view->addAction(
       id(new PhabricatorActionView())
         ->setName(pht('View History'))
         ->setHref($history_uri)
         ->setIcon('history'));
 
     $behind_head = $drequest->getRawCommit();
     $head_uri = $drequest->generateURI(
       array(
         'commit' => '',
         'action' => 'browse',
       ));
     $view->addAction(
       id(new PhabricatorActionView())
         ->setName(pht('Jump to HEAD'))
         ->setHref($head_uri)
         ->setIcon('home')
         ->setDisabled(!$behind_head));
 
     // TODO: Ideally, this should live in Owners and be event-triggered, but
     // there's no reasonable object for it to react to right now.
 
-    $owners_uri = id(new PhutilURI('/owners/view/search/'))
-      ->setQueryParams(
-        array(
-          'repository' => $drequest->getCallsign(),
-          'path' => '/'.$drequest->getPath(),
-        ));
-
-    $view->addAction(
-      id(new PhabricatorActionView())
-        ->setName(pht('Find Owners'))
-        ->setHref((string)$owners_uri)
-        ->setIcon('preview'));
+    $owners = 'PhabricatorApplicationOwners';
+    if (PhabricatorApplication::isClassInstalled($owners)) {
+      $owners_uri = id(new PhutilURI('/owners/view/search/'))
+        ->setQueryParams(
+          array(
+            'repository' => $drequest->getCallsign(),
+            'path' => '/'.$drequest->getPath(),
+          ));
+
+      $view->addAction(
+        id(new PhabricatorActionView())
+          ->setName(pht('Find Owners'))
+          ->setHref((string)$owners_uri)
+          ->setIcon('preview'));
+    }
 
     return $view;
   }
 
   protected function buildPropertyView(
     DiffusionRequest $drequest,
     PhabricatorActionListView $actions) {
 
     $viewer = $this->getRequest()->getUser();
 
     $view = id(new PHUIPropertyListView())
       ->setUser($viewer)
       ->setActionList($actions);
 
     $stable_commit = $drequest->getStableCommitName();
     $callsign = $drequest->getRepository()->getCallsign();
 
     $view->addProperty(
       pht('Commit'),
       phutil_tag(
         'a',
         array(
           'href' => $drequest->generateURI(
             array(
               'action' => 'commit',
               'commit' => $stable_commit,
             )),
         ),
         $drequest->getRepository()->formatCommitName($stable_commit)));
 
     if ($drequest->getCommitType() == 'tag') {
       $symbolic = $drequest->getSymbolicCommit();
       $view->addProperty(pht('Tag'), $symbolic);
 
       $tags = $this->callConduitWithDiffusionRequest(
         'diffusion.tagsquery',
         array(
           'names' => array($symbolic),
           'needMessages' => true,
         ));
       $tags = DiffusionRepositoryTag::newFromConduit($tags);
 
       $tags = mpull($tags, null, 'getName');
       $tag = idx($tags, $symbolic);
 
       if ($tag && strlen($tag->getMessage())) {
         $view->addSectionHeader(pht('Tag Content'));
         $view->addTextContent($this->markupText($tag->getMessage()));
       }
     }
 
     return $view;
   }
 
   protected function buildOpenRevisions() {
     $user = $this->getRequest()->getUser();
 
     $drequest = $this->getDiffusionRequest();
     $repository = $drequest->getRepository();
     $path = $drequest->getPath();
 
     $path_map = id(new DiffusionPathIDQuery(array($path)))->loadPathIDs();
     $path_id = idx($path_map, $path);
     if (!$path_id) {
       return null;
     }
 
     $revisions = id(new DifferentialRevisionQuery())
       ->setViewer($user)
       ->withPath($repository->getID(), $path_id)
       ->withStatus(DifferentialRevisionQuery::STATUS_OPEN)
       ->setOrder(DifferentialRevisionQuery::ORDER_PATH_MODIFIED)
       ->setLimit(10)
       ->needRelationships(true)
       ->execute();
 
     if (!$revisions) {
       return null;
     }
 
     $view = id(new DifferentialRevisionListView())
       ->setRevisions($revisions)
       ->setFields(DifferentialRevisionListView::getDefaultFields($user))
       ->setUser($user)
       ->loadAssets();
 
     $phids = $view->getRequiredHandlePHIDs();
     $handles = $this->loadViewerHandles($phids);
     $view->setHandles($handles);
 
     return id(new PHUIObjectBoxView())
       ->setHeaderText(pht('Pending Differential Revisions'))
       ->appendChild($view);
 
   }
 
 }