diff --git a/inc/inc.ClassExtBase.php b/inc/inc.ClassExtBase.php
index 0ae1fd952..316ae52a6 100644
--- a/inc/inc.ClassExtBase.php
+++ b/inc/inc.ClassExtBase.php
@@ -22,18 +22,20 @@
 *  This copyright notice MUST APPEAR in all copies of the script!
 ***************************************************************/
 
+namespace Seeddms\Seeddms;
+
 /**
  * Base class for extensions
  *
  * @author  Uwe Steinmann <uwe@steinmann.cx>
  * @package SeedDMS
  */
-class SeedDMS_ExtBase {
+class ExtensionBase {
 	var $settings;
 	var $dms;
 	var $logger;
 
-	public function __construct($settings, $dms, $logger) {
+	public function __construct(Settings $settings, $dms, $logger) {
 		$this->settings = $settings;
 		$this->dms = $dms;
 		$this->logger = $logger;
diff --git a/inc/inc.ClassExtensionMgr.php b/inc/inc.ClassExtensionMgr.php
index 3f7a3577e..be648449f 100644
--- a/inc/inc.ClassExtensionMgr.php
+++ b/inc/inc.ClassExtensionMgr.php
@@ -750,5 +750,3 @@ $EXT_CONF = '.var_export($EXT_CONF, true).';');
 		return $this->errmsgs;
 	} /* }}} */
 }
-
-class_alias('Seeddms\Seeddms\ExtensionMgr', 'SeedDMS_Extension_Mgr');
diff --git a/inc/inc.Extension.php b/inc/inc.Extension.php
index c3a0b43e0..e0558f4e0 100644
--- a/inc/inc.Extension.php
+++ b/inc/inc.Extension.php
@@ -11,10 +11,20 @@
  * @version    Release: @package_version@
  */
 
-require "inc.ClassExtensionMgr.php";
-require_once "inc.ClassExtBase.php";
+//require_once "inc.ClassExtensionMgr.php";
+//require_once "inc.ClassExtBase.php";
 
-$extmgr = new SeedDMS_Extension_Mgr($settings->_rootDir."/ext", $settings->_cacheDir, $settings->_repositoryUrl, $settings->_proxyUrl, $settings->_proxyUser, $settings->_proxyPassword);
+// Do not set a namespace until all extensions use that namespace
+// or set the class name in the conf file to '\xxxx'
+//namespace Seeddms\Seeddms;
+
+use Seeddms\Seeddms\ExtensionMgr;
+
+class_alias('Seeddms\Seeddms\ExtensionMgr', 'SeedDMS_Extension_Mgr');
+/* Declare an alias as long as it used by extensions */
+class_alias('Seeddms\Seeddms\ExtensionBase', 'SeedDMS_ExtBase');
+
+$extmgr = new \Seeddms\Seeddms\ExtensionMgr($settings->_rootDir."/ext", $settings->_cacheDir, $settings->_repositoryUrl, $settings->_proxyUrl, $settings->_proxyUser, $settings->_proxyPassword);
 
 foreach($extmgr->getExtensionConfiguration() as $extname=>$extconf) {
 	if($extconf['disable']) {