diff --git a/web/lib/MRBS/DB_mysql.php b/web/lib/MRBS/DB_mysql.php
index 2f20ea417a..08db5d31b6 100644
--- a/web/lib/MRBS/DB_mysql.php
+++ b/web/lib/MRBS/DB_mysql.php
@@ -29,9 +29,9 @@ class DB_mysql extends DB
     );
 
   private const MIN_VERSIONS = array(
-      self::DB_MARIADB => '10.0.2',
-      self::DB_MYSQL   => '5.5.3',
-      self::DB_PERCONA => '5.5.3'
+      self::DB_MARIADB => '5.5.3', // '10.0.2' recommended for multiple lock support
+      self::DB_MYSQL   => '5.5.3', // '5.7.5' recommended for multiple lock support
+      self::DB_PERCONA => '5.5.3'  // '5.7.5' recommended for multiple lock support
     );
 
   private const DB_NAMES = array(