diff --git a/modules/user/user.pages.inc b/modules/user/user.pages.inc
index d447c7c..3591d05 100644
--- a/modules/user/user.pages.inc
+++ b/modules/user/user.pages.inc
@@ -157,7 +157,7 @@ function user_pass_reset($form, &$form_state, $uid, $timestamp, $hashed_pass, $a
         // First stage is a confirmation form, then login
         if ($action == 'login') {
           $user_agent = $_SERVER['HTTP_USER_AGENT'];
-          if (strpos($user_agent, 'BingPreview') !== FALSE) {
+          if (strpos($user_agent, 'BingPreview') !== FALSE || strpos($user_agent, 'Slackbot') !== FALSE) {
             // Deny access for the BingPreview bot, used by outlook.com on links
             // in e-mails.
             drupal_access_denied();