diff --git a/src/view/page/PhabricatorStandardPageView.php b/src/view/page/PhabricatorStandardPageView.php
--- a/src/view/page/PhabricatorStandardPageView.php
+++ b/src/view/page/PhabricatorStandardPageView.php
@@ -454,7 +454,7 @@
           $client_uri->setDomain($this_host->getDomain());
         }
 
-        if ($request->isHTTPS()) {
+        if ($client_uri->getProtocol() == 'https' or $request->isHTTPS()) {
           $client_uri->setProtocol('wss');
         } else {
           $client_uri->setProtocol('ws');