diff --git a/resources/celerity/map.php b/resources/celerity/map.php
--- a/resources/celerity/map.php
+++ b/resources/celerity/map.php
@@ -9,7 +9,7 @@
   'names' => array(
     'conpherence.pkg.css' => 'e68cf1fa',
     'conpherence.pkg.js' => '15191c65',
-    'core.pkg.css' => '39061f68',
+    'core.pkg.css' => 'c30f6eaa',
     'core.pkg.js' => 'e1f0f7bd',
     'differential.pkg.css' => '06dc617c',
     'differential.pkg.js' => 'c2ca903a',
@@ -38,7 +38,7 @@
     'rsrc/css/application/almanac/almanac.css' => 'dbb9b3af',
     'rsrc/css/application/auth/auth.css' => '0877ed6e',
     'rsrc/css/application/base/main-menu-view.css' => '1802a242',
-    'rsrc/css/application/base/notification-menu.css' => '10685bd4',
+    'rsrc/css/application/base/notification-menu.css' => 'ef480927',
     'rsrc/css/application/base/phui-theme.css' => '9f261c6b',
     'rsrc/css/application/base/standard-page-view.css' => '34ee718b',
     'rsrc/css/application/chatlog/chatlog.css' => 'd295b020',
@@ -768,7 +768,7 @@
     'phabricator-nav-view-css' => '694d7723',
     'phabricator-notification' => '4f774dac',
     'phabricator-notification-css' => '457861ec',
-    'phabricator-notification-menu-css' => '10685bd4',
+    'phabricator-notification-menu-css' => 'ef480927',
     'phabricator-object-selector-css' => '85ee8ce6',
     'phabricator-phtize' => 'd254d646',
     'phabricator-prefab' => '77b0ae28',
diff --git a/src/applications/notification/controller/PhabricatorNotificationPanelController.php b/src/applications/notification/controller/PhabricatorNotificationPanelController.php
--- a/src/applications/notification/controller/PhabricatorNotificationPanelController.php
+++ b/src/applications/notification/controller/PhabricatorNotificationPanelController.php
@@ -6,6 +6,10 @@
   public function handleRequest(AphrontRequest $request) {
     $viewer = $request->getViewer();
 
+    $unread_count = $viewer->getUnreadNotificationCount();
+
+    $warning = $this->prunePhantomNotifications($unread_count);
+
     $query = id(new PhabricatorNotificationQuery())
       ->setViewer($viewer)
       ->withUserPHIDs(array($viewer->getPHID()))
@@ -66,13 +70,12 @@
       ));
 
     $content = hsprintf(
-      '%s%s%s',
+      '%s%s%s%s',
       $header,
+      $warning,
       $content,
       $connection_ui);
 
-    $unread_count = $viewer->getUnreadNotificationCount();
-
     $json = array(
       'content' => $content,
       'number'  => (int)$unread_count,
@@ -80,4 +83,81 @@
 
     return id(new AphrontAjaxResponse())->setContent($json);
   }
+
+  private function prunePhantomNotifications($unread_count) {
+    // See T8953. If you have an unread notification about an object you
+    // do not have permission to view, it isn't possible to clear it by
+    // visiting the object. Identify these notifications and mark them as
+    // read.
+
+    $viewer = $this->getViewer();
+
+    if (!$unread_count) {
+      return null;
+    }
+
+    $table = new PhabricatorFeedStoryNotification();
+    $conn = $table->establishConnection('r');
+
+    $rows = queryfx_all(
+      $conn,
+      'SELECT chronologicalKey, primaryObjectPHID FROM %T
+        WHERE userPHID = %s AND hasViewed = 0',
+      $table->getTableName(),
+      $viewer->getPHID());
+    if (!$rows) {
+      return null;
+    }
+
+    $map = array();
+    foreach ($rows as $row) {
+      $map[$row['primaryObjectPHID']][] = $row['chronologicalKey'];
+    }
+
+    $handles = $viewer->loadHandles(array_keys($map));
+    $purge_keys = array();
+    foreach ($handles as $handle) {
+      $phid = $handle->getPHID();
+      if ($handle->isComplete()) {
+        continue;
+      }
+
+      foreach ($map[$phid] as $chronological_key) {
+        $purge_keys[] = $chronological_key;
+      }
+    }
+
+    if (!$purge_keys) {
+      return null;
+    }
+
+    $unguarded = AphrontWriteGuard::beginScopedUnguardedWrites();
+
+    $conn = $table->establishConnection('w');
+    queryfx(
+      $conn,
+      'UPDATE %T SET hasViewed = 1
+        WHERE userPHID = %s AND chronologicalKey IN (%Ls)',
+      $table->getTableName(),
+      $viewer->getPHID(),
+      $purge_keys);
+
+    PhabricatorUserCache::clearCache(
+      PhabricatorUserNotificationCountCacheType::KEY_COUNT,
+      $viewer->getPHID());
+
+    unset($unguarded);
+
+    return phutil_tag(
+      'div',
+      array(
+        'class' => 'phabricator-notification phabricator-notification-warning',
+      ),
+      pht(
+        '%s notification(s) about objects which no longer exist or which '.
+        'you can no longer see were discarded.',
+        phutil_count($purge_keys)));
+  }
+
+
 }
diff --git a/src/applications/notification/query/PhabricatorNotificationQuery.php b/src/applications/notification/query/PhabricatorNotificationQuery.php
--- a/src/applications/notification/query/PhabricatorNotificationQuery.php
+++ b/src/applications/notification/query/PhabricatorNotificationQuery.php
@@ -76,31 +76,31 @@
     return $stories;
   }
 
-  protected function buildWhereClause(AphrontDatabaseConnection $conn_r) {
-    $where = array();
+  protected function buildWhereClauseParts(AphrontDatabaseConnection $conn) {
+    $where = parent::buildWhereClauseParts($conn);
 
     if ($this->userPHIDs !== null) {
       $where[] = qsprintf(
-        $conn_r,
+        $conn,
         'notif.userPHID IN (%Ls)',
         $this->userPHIDs);
     }
 
     if ($this->unread !== null) {
       $where[] = qsprintf(
-        $conn_r,
+        $conn,
         'notif.hasViewed = %d',
         (int)!$this->unread);
     }
 
     if ($this->keys) {
       $where[] = qsprintf(
-        $conn_r,
+        $conn,
         'notif.chronologicalKey IN (%Ls)',
         $this->keys);
     }
 
-    return $this->formatWhereClause($where);
+    return $where;
   }
 
   protected function getResultCursor($item) {
diff --git a/src/infrastructure/internationalization/translation/PhabricatorUSEnglishTranslation.php b/src/infrastructure/internationalization/translation/PhabricatorUSEnglishTranslation.php
--- a/src/infrastructure/internationalization/translation/PhabricatorUSEnglishTranslation.php
+++ b/src/infrastructure/internationalization/translation/PhabricatorUSEnglishTranslation.php
@@ -1651,6 +1651,14 @@
         'Destroyed %s credentials of type "%s".',
       ),
 
+      '%s notification(s) about objects which no longer exist or which '.
+      'you can no longer see were discarded.' => array(
+        'One notification about an object which no longer exists or which '.
+        'you can no longer see was discarded.',
+        '%s notifications about objects which no longer exist or which '.
+        'you can no longer see were discarded.',
+      ),
+
     );
   }
 
diff --git a/webroot/rsrc/css/application/base/notification-menu.css b/webroot/rsrc/css/application/base/notification-menu.css
--- a/webroot/rsrc/css/application/base/notification-menu.css
+++ b/webroot/rsrc/css/application/base/notification-menu.css
@@ -68,6 +68,10 @@
   color: {$lightgreytext};
 }
 
+.phabricator-notification-warning {
+  background: {$sh-yellowbackground};
+}
+
 .phabricator-notification-list .phabricator-notification-unread,
 .phabricator-notification-menu .phabricator-notification-unread {
   background: {$hoverblue};
@@ -95,7 +99,7 @@
 .phabricator-notification-unread .phabricator-notification-foot
   .phabricator-notification-status {
     font-size: 7px;
-    color: {$lightgreytext};
+    color: {$lightbluetext};
     position: absolute;
     display: inline-block;
     top: 6px;