diff --git a/blocks/online_users/block_online_users.php b/blocks/online_users/block_online_users.php
index 06bec16b732..13c14ad7aef 100644
--- a/blocks/online_users/block_online_users.php
+++ b/blocks/online_users/block_online_users.php
@@ -89,7 +89,7 @@ class block_online_users extends block_base {
                 // user has a hidden role assigned at this context or any parent contexts,
                 // ignore this user
                 
-                $SQL = "SELECT id,id FROM {$CFG->prefix}role_assignments
+                $SQL = "SELECT id FROM {$CFG->prefix}role_assignments
                         WHERE userid = $puser->id
                         AND contextid $pcontext
                         AND hidden = 1";