diff --git a/actions/twitapiusers.php b/actions/twitapiusers.php
index 0461efcb4e..a47fdfbc38 100644
--- a/actions/twitapiusers.php
+++ b/actions/twitapiusers.php
@@ -45,7 +45,7 @@ class TwitapiusersAction extends TwitterapiAction
         }
 
         if (!$user) {
-            $this->client_error(_('Not found.'), 404, $apidata['content-type']);
+            $this->clientError(_('Not found.'), 404, $apidata['content-type']);
             return;
         }