diff --git a/upgrade.php b/upgrade.php
index fbb135af..05b17ec7 100644
--- a/upgrade.php
+++ b/upgrade.php
@@ -1021,8 +1021,13 @@ function upgrade_495_pgsql() {
 # See https://sourceforge.net/forum/message.php?msg_id=5394663
 function upgrade_495_mysql() {
     $table_mailbox = table_by_key('mailbox');
-    db_query_parsed("ALTER TABLE $table_mailbox add local_part varchar(255) "); // allow to be null
+    db_query_parsed("ALTER TABLE $table_mailbox add local_part varchar(255) AFTER quota"); // allow to be null
     db_query_parsed("UPDATE $table_mailbox SET local_part = substring_index(username, '@', 1)");
     db_query_parsed("ALTER TABLE $table_mailbox change local_part local_part varchar(255) NOT NULL"); // remove null-ness...
 }
 
+function upgrade_504_mysql() {
+    $table_mailbox = table_by_key('mailbox');
+    db_query_parsed("ALTER TABLE `$table_mailbox` CHANGE `local_part` `local_part` VARCHAR( 255 ) {LATIN1} NOT NULL");
+}
+