diff --git a/lib/openid.php b/lib/openid.php
index 5c3d460daf..3aa488b6d4 100644
--- a/lib/openid.php
+++ b/lib/openid.php
@@ -160,7 +160,7 @@ function oid_authenticate($openid_url, $returnto, $immediate=false)
         $auth_request->addExtension($sreg_request);
     }
 
-    $trust_root = common_local_url('public');
+    $trust_root = common_path('');
     $process_url = common_local_url($returnto);
 
     if ($auth_request->shouldSendRedirect()) {