diff --git a/src/includes/class.db.mysql.php b/src/includes/class.db.mysql.php
index 968e583..852453a 100644
--- a/src/includes/class.db.mysql.php
+++ b/src/includes/class.db.mysql.php
@@ -49,6 +49,7 @@ class Database_Mysql
 	private $affected = null;
 	var $lastQuery;
 	private $dbname;
+	var $prefix = '';
 
 	function __construct()
 	{
diff --git a/src/includes/class.db.mysqli.php b/src/includes/class.db.mysqli.php
index f57c642..515030e 100644
--- a/src/includes/class.db.mysqli.php
+++ b/src/includes/class.db.mysqli.php
@@ -31,6 +31,7 @@ class Database_Mysql
 {
 	private $dbh; //mysqli
 	private $dbname;
+	var $prefix = '';
 
 	function __construct()
 	{
diff --git a/src/includes/class.db.sqlite3.php b/src/includes/class.db.sqlite3.php
index 321ff38..2182869 100644
--- a/src/includes/class.db.sqlite3.php
+++ b/src/includes/class.db.sqlite3.php
@@ -47,6 +47,7 @@ class Database_Sqlite3
 	private $dbh;
 	private $affected = null;
 	var $lastQuery;
+	var $prefix = '';
 
 	function __construct()
 	{
diff --git a/src/includes/common.php b/src/includes/common.php
index c9a7468..be9d68c 100644
--- a/src/includes/common.php
+++ b/src/includes/common.php
@@ -124,12 +124,16 @@ class DBConnection
 	public static function instance()
 	{
         if (!isset(self::$instance)) {
-			//$c = __CLASS__;
-			$c = 'DBConnection';
-			self::$instance = new $c;
+			throw new Exception("DBConnection is not initialized");
         }
 		return self::$instance;
 	}
+
+	public static function setPrefix($prefix)
+	{
+		$db = self::instance();
+		$db->prefix = $prefix;
+	}
 }
 
 ?>
\ No newline at end of file
diff --git a/src/init.php b/src/init.php
index 8efeaba..e803e2d 100644
--- a/src/init.php
+++ b/src/init.php
@@ -55,7 +55,7 @@ if (Config::get('db') == 'mysql')
 	$db->dq("SET NAMES utf8");
 }
 
-# SQLite3 (pdo_sqlite)
+# SQLite3 Database
 elseif(Config::get('db') == 'sqlite')
 {
 	require_once(MTTINC. 'class.db.sqlite3.php');
@@ -66,7 +66,7 @@ else {
 	# It seems not installed
 	die("Not installed. Run <a href=setup.php>setup.php</a> first.");
 }
-$db->prefix = Config::get('prefix');
+DBConnection::setPrefix(Config::get('prefix'));
 
 //User can override language setting by cookies or query
 $forceLang = '';