diff --git a/lib/Doctrine/Connection/Sqlite.php b/lib/Doctrine/Connection/Sqlite.php
index dd5b8c8bc..643c0aec9 100644
--- a/lib/Doctrine/Connection/Sqlite.php
+++ b/lib/Doctrine/Connection/Sqlite.php
@@ -72,6 +72,15 @@ class Doctrine_Connection_Sqlite extends Doctrine_Connection_Common {
 
         parent::__construct($manager, $pdo);
     }
+    /**
+     * initializes database functions missing in sqlite
+     */
+    public function initFunctions() {
+        $this->dbh->sqliteCreateFunction('md5',    array('Doctrine_Expression_Sqlite', 'md5Impl'), 1);
+        $this->dbh->sqliteCreateFunction('mod',    array('Doctrine_Expression_Sqlite', 'modImpl'), 2);
+        $this->dbh->sqliteCreateFunction('concat', array('Doctrine_Expression_Sqlite', 'concatImpl'));
+        $this->dbh->sqliteCreateFunction('now', 'time', 0);
+    }
     /**
      * Set the transacton isolation level.
      *
diff --git a/lib/Doctrine/Expression/Sqlite.php b/lib/Doctrine/Expression/Sqlite.php
index db94d11a4..341cf7a7e 100644
--- a/lib/Doctrine/Expression/Sqlite.php
+++ b/lib/Doctrine/Expression/Sqlite.php
@@ -27,6 +27,32 @@ Doctrine::autoload('Doctrine_Expression');
  * @license     LGPL
  */
 class Doctrine_Expression_Sqlite extends Doctrine_Expression {
+    /**
+     * Returns the md5 sum of the data that SQLite's md5() function receives.
+     *
+     * @return string
+     */
+    public static function md5Impl($data) {
+        return md5($data);
+    }
+    /**
+     * Returns the modules of the data that SQLite's mod() function receives.
+     *
+     * @return string
+     */
+    public static function modImpl($dividend, $divisor) {
+        return $dividend % $divisor;
+    }
+
+    /**
+     * Returns a concattenation of the data that SQLite's concat() function receives.
+     *
+     * @return string
+     */
+    public static function concatImpl() {
+        $args = func_get_args();
+        return join( '', $args );
+    }
     /**
      * returns the regular expression operator 
      *