diff --git a/src/applications/meta/controller/PhabricatorApplicationDetailViewController.php b/src/applications/meta/controller/PhabricatorApplicationDetailViewController.php
index 259b3c743..beda1d894 100644
--- a/src/applications/meta/controller/PhabricatorApplicationDetailViewController.php
+++ b/src/applications/meta/controller/PhabricatorApplicationDetailViewController.php
@@ -1,93 +1,101 @@
 <?php
 
 final class PhabricatorApplicationDetailViewController
   extends PhabricatorApplicationsController{
 
   private $application;
 
   public function willProcessRequest(array $data) {
     $this->application = $data['application'];
   }
 
   public function processRequest() {
     $request = $this->getRequest();
     $user = $request->getUser();
 
     $selected = PhabricatorApplication::getByClass($this->application);
 
     if (!$selected) {
       return new Aphront404Response();
     }
 
     $title = $selected->getName();
 
     $crumbs = $this->buildApplicationCrumbs();
     $crumbs->addCrumb(
       id(new PhabricatorCrumbView())
         ->setName(pht('Applications'))
         ->setHref($this->getApplicationURI()));
 
    $properties = $this->buildPropertyView($selected);
    $actions = $this->buildActionView($user, $selected);
 
    return $this->buildApplicationPage(
     array(
       $crumbs,
       id(new PhabricatorHeaderView())->setHeader($title),
       $actions,
       $properties,
     ),
     array(
       'title' => $title,
       'device' => true,
     ));
   }
 
   private function buildPropertyView(PhabricatorApplication $selected) {
     $properties = new PhabricatorPropertyListView();
 
     if ($selected->isInstalled()) {
       $properties->addProperty(
         pht('Status'), pht('Installed'));
 
     } else {
       $properties->addProperty(
         pht('Status'), pht('Uninstalled'));
     }
 
     $properties->addProperty(
       pht('Description'), $selected->getShortDescription());
 
     return $properties;
   }
 
   private function buildActionView(
     PhabricatorUser $user, PhabricatorApplication $selected) {
 
+    $view = id(new PhabricatorActionListView())
+          ->setUser($user);
+
     if ($selected->canUninstall()) {
       if ($selected->isInstalled()) {
-
-        return id(new PhabricatorActionListView())
-          ->setUser($user)
-          ->addAction(
-            id(new PhabricatorActionView())
-              ->setName(pht('Uninstall'))
-              ->setIcon('delete')
-              ->setHref(
+        $view->addAction(
+               id(new PhabricatorActionView())
+               ->setName(pht('Uninstall'))
+               ->setIcon('delete')
+               ->setHref(
                 $this->getApplicationURI(get_class($selected).'/uninstall/'))
-              );
+               );
       } else {
-          return id(new PhabricatorActionListView())
-            ->setUser($user)
-            ->addAction(
-              id(new PhabricatorActionView())
-              ->setName(pht('Install'))
-              ->setIcon('new')
-              ->setHref(
-                $this->getApplicationURI(get_class($selected).'/install/'))
-              );
+        $view->addAction(
+               id(new PhabricatorActionView())
+               ->setName(pht('Install'))
+               ->setIcon('new')
+               ->setHref(
+                 $this->getApplicationURI(get_class($selected).'/install/'))
+               );
       }
+    } else {
+      $view->addAction(
+             id(new PhabricatorActionView())
+             ->setName(pht('Uninstall'))
+             ->setIcon('delete')
+             ->setDisabled(true)
+             ->setHref(
+               $this->getApplicationURI(get_class($selected).'/uninstall/'))
+             );
     }
+    return $view;
   }
 
 }
diff --git a/src/applications/meta/controller/PhabricatorApplicationUninstallController.php b/src/applications/meta/controller/PhabricatorApplicationUninstallController.php
index fcf32ea4a..51b03cb08 100644
--- a/src/applications/meta/controller/PhabricatorApplicationUninstallController.php
+++ b/src/applications/meta/controller/PhabricatorApplicationUninstallController.php
@@ -1,102 +1,112 @@
 <?php
 
 final class PhabricatorApplicationUninstallController
   extends PhabricatorApplicationsController {
 
   private $application;
   private $action;
 
   public function willProcessRequest(array $data) {
     $this->application = $data['application'];
     $this->action = $data['action'];
   }
 
   public function processRequest() {
     $request = $this->getRequest();
     $user = $request->getUser();
 
     $selected = PhabricatorApplication::getByClass($this->application);
 
-    if (!$selected || !$selected->canUninstall()) {
+    if (!$selected) {
       return new Aphront404Response();
     }
 
     if ($request->isDialogFormPost()) {
       $this->manageApplication();
      return id(new AphrontRedirectResponse())->setURI('/applications/');
     }
 
-    if ($this->action == 'install') {
+    $dialog = id(new AphrontDialogView())
+               ->setUser($user)
+               ->addCancelButton('/applications/view/'.$this->application);
 
-      $dialog = id(new AphrontDialogView())
-             ->setUser($user)
-             ->setTitle('Confirmation')
-             ->appendChild(
-               'Install '. $selected->getName(). ' application ?'
-               )
-             ->addSubmitButton('Install')
-             ->addCancelButton('/applications/view/'.$this->application);
+    if ($this->action == 'install') {
+      if ($selected->canUninstall()) {
+        $dialog->setTitle('Confirmation')
+               ->appendChild(
+                 'Install '. $selected->getName(). ' application ?'
+                 )
+               ->addSubmitButton('Install');
+
+      } else {
+        $dialog->setTitle('Information')
+               ->appendChild('You cannot install a installed application.');
+      }
     } else {
-      $dialog = id(new AphrontDialogView())
-             ->setUser($user)
-             ->setTitle('Confirmation')
-             ->appendChild(
-               'Really Uninstall '. $selected->getName(). ' application ?'
-               )
-             ->addSubmitButton('Uninstall')
-             ->addCancelButton('/applications/view/'.$this->application);
+      if ($selected->canUninstall()) {
+        $dialog->setTitle('Confirmation')
+               ->appendChild(
+                 'Really Uninstall '. $selected->getName(). ' application ?'
+                 )
+               ->addSubmitButton('Uninstall');
+      } else {
+        $dialog->setTitle('Information')
+               ->appendChild(
+                 'This application cannot be uninstalled,
+                 because it is required for Phabricator to work.'
+                 );
+      }
     }
-
     return id(new AphrontDialogResponse())->setDialog($dialog);
   }
 
   public function manageApplication() {
     $key = 'phabricator.uninstalled-applications';
 
     $config_entry = id(new PhabricatorConfigEntry())
                  ->loadOneWhere(
                    'configKey = %s AND namespace = %s',
                     $key,
                    'default');
 
     if (!$config_entry) {
       $config_entry = id(new PhabricatorConfigEntry())
                    ->setConfigKey($key)
                    ->setNamespace('default');
   }
 
   $list = $config_entry->getValue();
 
   $uninstalled = PhabricatorEnv::getEnvConfig($key);
 
   if ($uninstalled[$this->application]) {
     unset($list[$this->application]);
   } else {
       $list[$this->application] = true;
   }
 
   $xaction = id(new PhabricatorConfigTransaction())
             ->setTransactionType(PhabricatorConfigTransaction::TYPE_EDIT)
             ->setNewValue(
               array(
                  'deleted' => false,
                  'value' => $list
               ));
 
   $editor = id(new PhabricatorConfigEditor())
          ->setActor($this->getRequest()->getUser())
          ->setContinueOnNoEffect(true)
          ->setContentSource(
            PhabricatorContentSource::newForSource(
              PhabricatorContentSource::SOURCE_WEB,
              array(
                'ip' => $this->getRequest()->getRemoteAddr(),
              )));
 
 
   $editor->applyTransactions($config_entry, array($xaction));
 
   }
 
 }