diff --git a/_config/extensions.yml b/_config/extensions.yml
index 1276494..15487c4 100644
--- a/_config/extensions.yml
+++ b/_config/extensions.yml
@@ -4,6 +4,9 @@ Name: extensions
 CMSMain:
   extensions:
     ['MultisitesCMSMainExtension']
+Controller:
+  extensions:
+    ['MultisitesControllerExtension']
 ContentController:
   extensions:
     ['MultisitesContentControllerExtension']
diff --git a/code/controllers/MultisitesFrontController.php b/code/controllers/MultisitesFrontController.php
index 260ee3a..23ed748 100644
--- a/code/controllers/MultisitesFrontController.php
+++ b/code/controllers/MultisitesFrontController.php
@@ -15,7 +15,7 @@ public function getNestedController() {
 		$site    = Multisites::inst()->getCurrentSiteId();
 
 		if(!$site) {
-			return $this->getNotFoundResponse();
+			return $this->httpError(404);
 		}
 
 		if(class_exists('Translatable')) Translatable::disable_locale_filter();
@@ -83,7 +83,7 @@ public function getNestedController() {
 				return $this->response;
 			}
 
-			return $this->getNotFoundResponse($site);
+			return $this->httpError(404);
 		}
 
 		if(class_exists('Translatable') && $page->Locale) {
@@ -93,25 +93,4 @@ public function getNestedController() {
 		return self::controller_for($page, $request->param('Action'));
 	}
 
-
-	/**
-	 * Finds the current site's ErrorPage of ErrorCode 404, to redirect the user to
-	 * if the requested page is not found
-	 **/
-	protected function getNotFoundResponse($siteId = null) {
-		$page = ErrorPage::get()->filter(array(
-			'ErrorCode' => 404,
-			'SiteID'    => $siteId ?: Multisites::inst()->getDefaultSiteId()
-		));
-
-		if($page = $page->first()) {
-			$controller = ModelAsController::controller_for($page);
-			$request    = new SS_HTTPRequest('GET', '');
-
-			return $controller->handleRequest($request, $this->model);
-		} else {
-			return new SS_HTTPResponse(null, 404);
-		}
-	}
-
 }
diff --git a/code/controllers/MultisitesRootController.php b/code/controllers/MultisitesRootController.php
index dee36ae..bce57c6 100644
--- a/code/controllers/MultisitesRootController.php
+++ b/code/controllers/MultisitesRootController.php
@@ -12,7 +12,7 @@ public function handleRequest(SS_HTTPRequest $request, DataModel $model = null)
 		$this->init();
 
 		if(!$site = Multisites::inst()->getCurrentSiteId()) {
-			return $this->getNotFoundResponse();
+			return $this->httpError(404);
 		}
 
 		$page = SiteTree::get()->filter(array(
@@ -21,7 +21,7 @@ public function handleRequest(SS_HTTPRequest $request, DataModel $model = null)
 		));
 
 		if(!$page = $page->first()) {
-			return $this->getNotFoundResponse($site);
+			return $this->httpError(404);
 		}
 
 		$request = new SS_HTTPRequest(
@@ -38,22 +38,6 @@ public function handleRequest(SS_HTTPRequest $request, DataModel $model = null)
 		$this->popCurrent();
 		return $response;
 	}
-
-	protected function getNotFoundResponse($siteId = null) {
-		$page = ErrorPage::get()->filter(array(
-			'ErrorCode' => 404,
-			'SiteID'    => $siteId ?: Multisites::inst()->getDefaultSiteId()
-		));
-
-		if($page = $page->first()) {
-			$controller = ModelAsController::controller_for($page);
-			$request    = new SS_HTTPRequest('GET', '');
-
-			return $controller->handleRequest($request, $this->model);
-		} else {
-			return new SS_HTTPResponse(null, 404);
-		}
-	}
 	
 	/**
 	 * The the (relative) homepage link.
diff --git a/code/controllers/RobotsTxtController.php b/code/controllers/RobotsTxtController.php
index 4dd9aef..b80e6b7 100644
--- a/code/controllers/RobotsTxtController.php
+++ b/code/controllers/RobotsTxtController.php
@@ -19,7 +19,7 @@ public function index() {
         $site    = Multisites::inst()->getCurrentSiteId();
 
         if(!$site) {
-            return $this->getNotFoundResponse();
+            return $this->httpError(404);
         }
 
         $page = Site::get()->filter(array(
@@ -29,7 +29,7 @@ public function index() {
         $page = $page->first();
 
         if(!$page) {
-            return $this->getNotFoundResponse();
+            return $this->httpError(404);
         }
 
         /*
@@ -41,30 +41,11 @@ public function index() {
         $text = trim($page->RobotsTxt);
 
         if(empty($text)) {
-            return $this->getNotFoundResponse();
+            return $this->httpError(404);
         }
 
         $this->getResponse()->addHeader('Content-Type', 'text/plain; charset="utf-8"');
         return $text;
     }
 
-    /**
-     * Finds the current site's ErrorPage of ErrorCode 404, to redirect the user to
-     * if the requested page is not found.
-     **/
-    protected function getNotFoundResponse($siteId = null) {
-        $page = ErrorPage::get()->filter(array(
-            'ErrorCode' => 404,
-            'SiteID'    => $siteId ?: Multisites::inst()->getDefaultSiteId()
-        ));
-
-        if($page = $page->first()) {
-            $controller = ModelAsController::controller_for($page);
-            $request    = new SS_HTTPRequest('GET', '');
-
-            return $controller->handleRequest($request, $this->model);
-        } else {
-            return new SS_HTTPResponse(null, 404);
-        }
-    }
 }
\ No newline at end of file
diff --git a/code/extensions/MultisitesControllerExtension.php b/code/extensions/MultisitesControllerExtension.php
new file mode 100644
index 0000000..13a8fae
--- /dev/null
+++ b/code/extensions/MultisitesControllerExtension.php
@@ -0,0 +1,29 @@
+<?php
+
+/**
+ *	@author Nathan Glasl <nathan@silverstripe.com.au>
+ */
+
+class MultisitesControllerExtension extends Extension {
+
+	/**
+	 *	Retrieve the correct error page for the current multisite instance.
+	 *	@param integer
+	 *	@param SS_HTTPRequest
+	 *	@throws SS_HTTPResponse_Exception
+	 */
+	public function onBeforeHTTPError($code, $request) {
+
+		$errorPage = ErrorPage::get()->filter(array(
+			'ErrorCode' => $code,
+			'SiteID' => Multisites::inst()->getCurrentSiteId()
+		))->first();
+		if($errorPage) {
+			Requirements::clear();
+			Requirements::clear_combined_files();
+			$response = ModelAsController::controller_for($errorPage)->handleRequest($request, DataModel::inst());
+			throw new SS_HTTPResponse_Exception($response, $code);
+		}
+	}
+
+}
diff --git a/code/extensions/MultisitesErrorPageExtension.php b/code/extensions/MultisitesErrorPageExtension.php
index 9266be9..1e9a742 100644
--- a/code/extensions/MultisitesErrorPageExtension.php
+++ b/code/extensions/MultisitesErrorPageExtension.php
@@ -22,10 +22,5 @@ public function alternateFilepathForErrorcode($code, $locale) {
 
 		return sprintf("%s/error-%s.html", $path, implode('-', $parts));
 	}
-	
-	public function augmentSQL(\SQLQuery &$query) {
-		if (Multisites::inst()->getCurrentSiteId()) {
-			$query->addWhere('"SiteID" = ' . Multisites::inst()->getCurrentSiteId());
-		}
-	}
+
 }