diff --git a/_config.php b/_config.php
index 325e9f9..2e4f5ea 100644
--- a/_config.php
+++ b/_config.php
@@ -5,15 +5,14 @@
  * about a number of sub-sites, rather than a single site.
  */
 
-Object::add_extension('SiteTree', 'SiteTreeSubsites');
-Object::add_extension('ContentController', 'ControllerSubsites');
-Object::add_extension('LeftAndMain', 'LeftAndMainSubsites');
-Object::add_extension('LeftAndMain', 'ControllerSubsites');
-
-Object::add_extension('Group', 'GroupSubsites');
-Object::add_extension('File', 'FileSubsites');
-Object::add_extension('ErrorPage', 'ErrorPageSubsite');
-Object::add_extension('SiteConfig', 'SiteConfigSubsites');
+SiteTree::add_extension('SiteTreeSubsites');
+ContentController::add_extension('ControllerSubsites');
+LeftAndMain::add_extension('LeftAndMainSubsites');
+LeftAndMain::add_extension('ControllerSubsites');
 
+Group::add_extension('GroupSubsites');
+File::add_extension('FileSubsites');
+ErrorPage::add_extension('ErrorPageSubsite');
+SiteConfig::add_extension('SiteConfigSubsites');
 
 SS_Report::add_excluded_reports('SubsiteReportWrapper');
diff --git a/code/extensions/ErrorPageSubsite.php b/code/extensions/ErrorPageSubsite.php
index 2cd468d..0e620ca 100644
--- a/code/extensions/ErrorPageSubsite.php
+++ b/code/extensions/ErrorPageSubsite.php
@@ -10,7 +10,7 @@ class ErrorPageSubsite extends DataExtension {
 	 * opening ErrorPage in the CMS and publish ErrorPage causes static error page to get generated incorrectly. 
 	 */
 	function alternateFilepathForErrorcode($statusCode, $locale = null) {
-		$static_filepath = Object::get_static($this->owner->ClassName, 'static_filepath');
+		$static_filepath = Config::inst()->get($this->owner->ClassName, 'static_filepath');
 		$subdomainPart = "";
 		
 		// Try to get current subsite from session