diff --git a/auth/ldap/auth.php b/auth/ldap/auth.php
index 15ec0bc..609d0e1 100644
--- a/auth/ldap/auth.php
+++ b/auth/ldap/auth.php
@@ -549,6 +549,7 @@ class auth_plugin_ldap extends auth_plugin_base {
     function sync_users ($bulk_insert_records = 1000, $do_updates = true) {
 
         global $CFG;
+        global $db;
 
         $textlib = textlib_get_instance();
 
@@ -563,24 +564,24 @@ class auth_plugin_ldap extends auth_plugin_base {
         switch (strtolower($CFG->dbfamily)) {
             case 'mysql':
                 $droptablesql[] = 'DROP TEMPORARY TABLE ' . $temptable; // sql command to drop the table (because session scope could be a problem)
-                $createtemptablesql = 'CREATE TEMPORARY TABLE ' . $temptable . ' (username VARCHAR(64), PRIMARY KEY (username)) TYPE=MyISAM';
+                $createtemptablesql = 'CREATE TEMPORARY TABLE ' . $temptable . ' (username VARCHAR(100), mnethostid BIGINT(10), PRIMARY KEY (username, mnethostid)) TYPE=MyISAM COLLATE utf8_general_ci';
                 break;
             case 'postgres':
                 $droptablesql[] = 'DROP TABLE ' . $temptable; // sql command to drop the table (because session scope could be a problem)
                 $bulk_insert_records = 1; // no support for multiple sets of values
-                $createtemptablesql = 'CREATE TEMPORARY TABLE '. $temptable . ' (username VARCHAR(64), PRIMARY KEY (username))';
+                $createtemptablesql = 'CREATE TEMPORARY TABLE '. $temptable . ' (username VARCHAR(100), mnethostid BIGINT, PRIMARY KEY (username, mnethostid))';
                 break;
             case 'mssql':
                 $temptable = '#'. $temptable; /// MSSQL temp tables begin with #
                 $droptablesql[] = 'DROP TABLE ' . $temptable; // sql command to drop the table (because session scope could be a problem)
                 $bulk_insert_records = 1; // no support for multiple sets of values
-                $createtemptablesql = 'CREATE TABLE ' . $temptable . ' (username VARCHAR(64), PRIMARY KEY (username))';
+                $createtemptablesql = 'CREATE TABLE ' . $temptable . ' (username VARCHAR(100), mnethostid BIGINT, PRIMARY KEY (username, mnethostid))';
                 break;
             case 'oracle':
                 $droptablesql[] = 'TRUNCATE TABLE ' . $temptable; // oracle requires truncate before being able to drop a temp table
                 $droptablesql[] = 'DROP TABLE ' . $temptable; // sql command to drop the table (because session scope could be a problem)
                 $bulk_insert_records = 1; // no support for multiple sets of values
-                $createtemptablesql = 'CREATE GLOBAL TEMPORARY TABLE '.$temptable.' (username VARCHAR(64), PRIMARY KEY (username)) ON COMMIT PRESERVE ROWS';
+                $createtemptablesql = 'CREATE GLOBAL TEMPORARY TABLE '.$temptable.' (username VARCHAR(100), mnethostid NUMBER(10), PRIMARY KEY (username, mnethostid)) ON COMMIT PRESERVE ROWS';
                 break;
         }
 
@@ -673,7 +674,8 @@ class auth_plugin_ldap extends auth_plugin_base {
         if (!empty($this->config->removeuser)) {
             $sql = "SELECT u.id, u.username, u.email, u.auth 
                     FROM {$CFG->prefix}user u
-                        LEFT JOIN $temptable e ON u.username = e.username
+                        LEFT JOIN $temptable e ON u.username = e.username 
+                                              AND u.mnethostid = e.mnethostid
                     WHERE u.auth='ldap'
                         AND u.deleted=0
                         AND e.username IS NULL";
@@ -711,6 +713,7 @@ class auth_plugin_ldap extends auth_plugin_base {
             $sql = "SELECT u.id, u.username
                     FROM $temptable e, {$CFG->prefix}user u
                     WHERE e.username=u.username
+                        AND e.mnethostid=u.mnethostid
                         AND u.auth='nologin'";
             $revive_users = get_records_sql($sql);
 
@@ -815,6 +818,7 @@ class auth_plugin_ldap extends auth_plugin_base {
         // note: we do not care about deleted accounts anymore, this feature was replaced by suspending to nologin auth plugin
         $sql = "SELECT e.username, e.username
                 FROM $temptable e LEFT JOIN {$CFG->prefix}user u ON e.username = u.username
+                                                                AND e.mnethostid = u.mnethostid
                 WHERE u.id IS NULL";
         $add_users = get_records_sql($sql); // get rid of the fat
 
@@ -929,13 +933,14 @@ class auth_plugin_ldap extends auth_plugin_base {
      * @param array $users is an array of usernames
      */
     function ldap_bulk_insert($users, $temptable) {
+        global $CFG;
 
         // bulk insert -- superfast with $bulk_insert_records
-        $sql = 'INSERT INTO ' . $temptable . ' (username) VALUES ';
+        $sql = 'INSERT INTO ' . $temptable . ' (username, mnethostid) VALUES ';
         // make those values safe
         $users = addslashes_recursive($users);
         // join and quote the whole lot
-        $sql = $sql . "('" . implode("'),('", $users) . "')";
+        $sql = $sql . "('" . implode("', $CFG->mnet_localhost_id),('", $users) . "', $CFG->mnet_localhost_id)";
         print "\t+ " . count($users) . " users\n";
         execute_sql($sql, false);
     }