diff --git a/.travis.yml b/.travis.yml
index d4ed1d5..8794572 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,33 +5,23 @@ sudo: false
 language: php
 
 php:
-  - 5.3
-  - 5.4
   - 5.5
   - 5.6
   - 7.0
 
 env:
-  - DB=MYSQL CORE_RELEASE=3.2
+  - DB=MYSQL CORE_RELEASE=master
 
 matrix:
   include:
     - php: 5.6
-      env: DB=MYSQL CORE_RELEASE=3
-    - php: 5.6
-      env: DB=MYSQL CORE_RELEASE=3.1
-    - php: 5.6
-      env: DB=PGSQL CORE_RELEASE=3.2
-  allow_failures:
-    - php: 7.0
+      env: DB=PGSQL CORE_RELEASE=master
 
 before_script:
   - composer self-update || true
   - git clone git://github.com/silverstripe-labs/silverstripe-travis-support.git ~/travis-support
   - php ~/travis-support/travis_setup.php --source `pwd` --target ~/builds/ss
   - cd ~/builds/ss
-  - composer install
-  - composer require wilr/silverstripe-googlesitemaps
 
 script:
   - vendor/bin/phpunit googlesitemaps/tests
diff --git a/_config.php b/_config.php
deleted file mode 100644
index 07af9ac..0000000
--- a/_config.php
+++ /dev/null
@@ -1,11 +0,0 @@
-<?php
-
-// add the extension to pages
-if (class_exists('SiteTree')) {
-	SiteTree::add_extension('GoogleSitemapSiteTreeExtension');
-}
-
-// if you need to add this to DataObjects include the following in
-// your own _config:
-
-// GoogleSiteMap::register_dataobject('MyDataObject');
diff --git a/_config/googlesitemaps.yml b/_config/googlesitemaps.yml
index 676a441..c7338db 100644
--- a/_config/googlesitemaps.yml
+++ b/_config/googlesitemaps.yml
@@ -5,4 +5,11 @@ GoogleSitemap:
   enabled: true
   objects_per_sitemap: 1000
   google_notification_enabled: false
-  use_show_in_search: true
\ No newline at end of file
+  use_show_in_search: true
+---
+Only:
+  classexists: SilverStripe\CMS\Model\SiteTree
+---
+SilverStripe\CMS\Model\SiteTree:
+  extensions:
+    - GoogleSitemapSiteTreeExtension
diff --git a/_config/routes.yml b/_config/routes.yml
index 63e07b3..86e765b 100644
--- a/_config/routes.yml
+++ b/_config/routes.yml
@@ -1,6 +1,6 @@
 ---
 Name: googlesitemaproutes
 ---
-Director:
+SilverStripe\Control\Director:
   rules:
-    'sitemap.xml': 'GoogleSitemapController'
\ No newline at end of file
+    'sitemap.xml': 'GoogleSitemapController'
diff --git a/code/GoogleSitemap.php b/code/GoogleSitemap.php
index fe169b9..947117a 100644
--- a/code/GoogleSitemap.php
+++ b/code/GoogleSitemap.php
@@ -1,4 +1,15 @@
 <?php
+
+use SilverStripe\CMS\Model\SiteTree;
+use SilverStripe\Control\Director;
+use SilverStripe\Core\ClassInfo;
+use SilverStripe\Core\Config\Config;
+use SilverStripe\Core\Object;
+use SilverStripe\ORM\ArrayList;
+use SilverStripe\ORM\DataList;
+use SilverStripe\ORM\Versioning\Versioned;
+use SilverStripe\View\ArrayData;
+
 /**
  * Sitemaps are a way to tell Google about pages on your site that they might
  * not otherwise discover. In its simplest terms, a XML Sitemap usually called
@@ -225,8 +236,8 @@ class GoogleSitemap extends Object
             Translatable::disable_locale_filter();
         }
 
-        if ($class == "SiteTree") {
-            $instances = Versioned::get_by_stage('SiteTree', 'Live');
+        if ($class == SiteTree::class) {
+            $instances = Versioned::get_by_stage(SiteTree::class, 'Live');
 
             if($filter) {
                 $instances = $instances->filter('ShowInSearch', 1);
@@ -341,7 +352,7 @@ class GoogleSitemap extends Object
         $sitemaps = new ArrayList();
         $filter = Config::inst()->get('GoogleSitemap', 'use_show_in_search');
 
-        if (class_exists('SiteTree')) {
+        if (class_exists(SiteTree::class)) {
             // move to extension hook. At the moment moduleexists config hook
             // does not work.
             if (class_exists('Translatable')) {
@@ -349,7 +360,7 @@ class GoogleSitemap extends Object
             }
 
             $filter = ($filter) ? "\"ShowInSearch\" = 1" : "";
-            $class = 'SiteTree';
+            $class = SiteTree::class;
             $instances = Versioned::get_by_stage($class, 'Live', $filter);
             $this->extend("alterDataList", $instances, $class);
             $count = $instances->count();
@@ -365,7 +376,7 @@ class GoogleSitemap extends Object
                 $lastModified = ($lastEdited) ? date('Y-m-d', strtotime($lastEdited)) : date('Y-m-d');
 
                 $sitemaps->push(new ArrayData(array(
-                    'ClassName' => 'SiteTree',
+                    'ClassName' => $this->sanitiseClassName(SiteTree::class),
                     'LastModified' => $lastModified,
                     'Page' => $i
                 )));
diff --git a/code/controllers/GoogleSitemapController.php b/code/controllers/GoogleSitemapController.php
index 334c60b..75d86a7 100644
--- a/code/controllers/GoogleSitemapController.php
+++ b/code/controllers/GoogleSitemapController.php
@@ -1,7 +1,12 @@
 <?php
 
+use SilverStripe\CMS\Model\SiteTree;
+use SilverStripe\Control\Controller;
+use SilverStripe\Core\Config\Config;
+use SilverStripe\Control\HTTPResponse;
+
 /**
- * Controller for displaying the sitemap.xml. The module displays an index 
+ * Controller for displaying the sitemap.xml. The module displays an index
  * sitemap at the sitemap.xml level, then outputs the individual objects
  * at a second level.
  *
@@ -34,7 +39,7 @@ class GoogleSitemapController extends Controller
     {
         if (GoogleSitemap::enabled()) {
             Config::inst()->update('SSViewer', 'set_source_file_comments', false);
-            
+
             $this->getResponse()->addHeader('Content-Type', 'application/xml; charset="utf-8"');
             $this->getResponse()->addHeader('X-Robots-Tag', 'noindex');
 
@@ -45,14 +50,14 @@ class GoogleSitemapController extends Controller
                 'Sitemaps' => $sitemaps
             );
         } else {
-            return new SS_HTTPResponse('Page not found', 404);
+            return new HTTPResponse('Page not found', 404);
         }
     }
 
     /**
-     * Specific controller action for displaying a particular list of links 
+     * Specific controller action for displaying a particular list of links
      * for a class
-     * 
+     *
      * @return mixed
      */
     public function sitemap()
@@ -60,9 +65,9 @@ class GoogleSitemapController extends Controller
         $class = $this->unsanitiseClassName($this->request->param('ID'));
         $page = $this->request->param('OtherID');
 
-        if (GoogleSitemap::enabled() && $class && $page && ($class == 'SiteTree' || $class == 'GoogleSitemapRoute' || GoogleSitemap::is_registered($class))) {
+        if (GoogleSitemap::enabled() && $class && $page && ($class == SiteTree::class || $class == 'GoogleSitemapRoute' || GoogleSitemap::is_registered($class))) {
             Config::inst()->update('SSViewer', 'set_source_file_comments', false);
-            
+
             $this->getResponse()->addHeader('Content-Type', 'application/xml; charset="utf-8"');
             $this->getResponse()->addHeader('X-Robots-Tag', 'noindex');
 
@@ -73,7 +78,7 @@ class GoogleSitemapController extends Controller
                 'Items' => $items
             );
         } else {
-            return new SS_HTTPResponse('Page not found', 404);
+            return new HTTPResponse('Page not found', 404);
         }
     }
 
diff --git a/code/extensions/GoogleSitemapExtension.php b/code/extensions/GoogleSitemapExtension.php
index ac5907c..f3f95a9 100644
--- a/code/extensions/GoogleSitemapExtension.php
+++ b/code/extensions/GoogleSitemapExtension.php
@@ -1,5 +1,9 @@
 <?php
 
+use SilverStripe\Control\Director;
+use SilverStripe\ORM\DataExtension;
+use SilverStripe\ORM\FieldType\DBDatetime;
+
 /**
  * Decorate the page object to provide google sitemaps with
  * additionally options and configuration.
@@ -86,7 +90,7 @@ class GoogleSitemapExtension extends DataExtension
      *
      * @see http://support.google.com/webmasters/bin/answer.py?hl=en&answer=183668&topic=8476&ctx=topic
      *
-     * @return SS_Datetime
+     * @return DBDatetime
      */
     public function getChangeFrequency()
     {
@@ -96,10 +100,10 @@ class GoogleSitemapExtension extends DataExtension
 
         $date = date('Y-m-d H:i:s');
 
-        $created = new SS_Datetime();
+        $created = new DBDatetime();
         $created->value = ($this->owner->Created) ? $this->owner->Created : $date;
 
-        $now = new SS_Datetime();
+        $now = new DBDatetime();
         $now->value = $date;
 
         $versions = ($this->owner->Version) ? $this->owner->Version : 1;
diff --git a/code/extensions/GoogleSitemapSiteTreeExtension.php b/code/extensions/GoogleSitemapSiteTreeExtension.php
index f448769..779ef3a 100644
--- a/code/extensions/GoogleSitemapSiteTreeExtension.php
+++ b/code/extensions/GoogleSitemapSiteTreeExtension.php
@@ -1,5 +1,10 @@
 <?php
 
+use SilverStripe\CMS\Model\ErrorPage;
+use SilverStripe\Forms\DropdownField;
+use SilverStripe\Forms\LiteralField;
+use SilverStripe\Forms\Tab;
+
 /**
  * @package googlesitemaps
  */
@@ -33,13 +38,13 @@ class GoogleSitemapSiteTreeExtension extends GoogleSitemapExtension
         );
 
         $tabset = $fields->findOrMakeTab('Root.Settings');
-        
+
         $message = "<p>";
         $message .= sprintf(_t('GoogleSitemaps.METANOTEPRIORITY', "Manually specify a Google Sitemaps priority for this page (%s)"),
             '<a href="http://www.google.com/support/webmasters/bin/answer.py?hl=en&answer=71936#prioritize" target="_blank">?</a>'
         );
         $message .=  "</p>";
-        
+
         $tabset->push(new Tab('GoogleSitemap', _t('GoogleSitemaps.TABGOOGLESITEMAP', 'Google Sitemap'),
             new LiteralField("GoogleSitemapIntro", $message),
             $priority = new DropdownField("Priority", $this->owner->fieldLabel('Priority'), $prorities, $this->owner->Priority)
@@ -59,26 +64,26 @@ class GoogleSitemapSiteTreeExtension extends GoogleSitemapExtension
 
         $labels['Priority'] = _t('GoogleSitemaps.METAPAGEPRIO', "Page Priority");
     }
-    
+
     /**
      * Ensure that all parent pages of this page (if any) are published
-     * 
+     *
      * @return boolean
      */
     public function hasPublishedParent()
     {
-        
+
         // Skip root pages
         if (empty($this->owner->ParentID)) {
             return true;
         }
-        
+
         // Ensure direct parent exists
         $parent = $this->owner->Parent();
         if (empty($parent) || !$parent->exists()) {
             return false;
         }
-        
+
         // Check ancestry
         return $parent->hasPublishedParent();
     }
@@ -88,12 +93,12 @@ class GoogleSitemapSiteTreeExtension extends GoogleSitemapExtension
      */
     public function canIncludeInGoogleSitemap()
     {
-        
+
         // Check that parent page is published
         if (!$this->owner->hasPublishedParent()) {
             return false;
         }
-        
+
         $result = parent::canIncludeInGoogleSitemap();
         $result = ($this->owner instanceof ErrorPage) ? false : $result;
 
@@ -111,7 +116,7 @@ class GoogleSitemapSiteTreeExtension extends GoogleSitemapExtension
         if (!$priority) {
             $parentStack = $this->owner->parentStack();
             $numParents = is_array($parentStack) ? count($parentStack) - 1 : 0;
-            
+
             $num = max(0.1, 1.0 - ($numParents / 10));
             $result = str_replace(",", ".", $num);
 
diff --git a/tests/GoogleSitemapTest.php b/tests/GoogleSitemapTest.php
index 99f9f03..2abbe90 100644
--- a/tests/GoogleSitemapTest.php
+++ b/tests/GoogleSitemapTest.php
@@ -1,5 +1,17 @@
 <?php
 
+use SilverStripe\CMS\Model\SiteTree;
+use SilverStripe\Control\Director;
+use SilverStripe\Core\Config\Config;
+use SilverStripe\Dev\FunctionalTest;
+use SilverStripe\Dev\TestOnly;
+use SilverStripe\Forms\DropdownField;
+use SilverStripe\Forms\LiteralField;
+use SilverStripe\Forms\Tab;
+use SilverStripe\ORM\DataObject;
+use SilverStripe\ORM\DB;
+use SilverStripe\ORM\Versioning\Versioned;
+
 /**
  * TODO: Migrate to new instance level interface instead of using static methods for retrieval of site maps and items (i.e. ->getSitemaps() instead of ::get_sitemaps()).
  *
@@ -25,7 +37,7 @@ class GoogleSitemapTest extends FunctionalTest
         if (class_exists('Page')) {
             $this->loadFixture('googlesitemaps/tests/GoogleSitemapPageTest.yml');
         }
-        
+
         GoogleSitemap::clear_registered_dataobjects();
         GoogleSitemap::clear_registered_routes();
     }
@@ -93,7 +105,7 @@ class GoogleSitemapTest extends FunctionalTest
         // dataobject as it hasn't been registered
         $expected = "<loc>". Director::absoluteURL("sitemap.xml/sitemap/GoogleSitemapTest_DataObject/1") ."</loc>";
         $this->assertEquals(1, substr_count($body, $expected), 'A link to GoogleSitemapTest_DataObject exists');
-        
+
         $expected = "<loc>". Director::absoluteURL("sitemap.xml/sitemap/GoogleSitemapTest_OtherDataObject/1") ."</loc>";
         $this->assertEquals(1, substr_count($body, $expected), 'A link to GoogleSitemapTest_OtherDataObject exists');
 
@@ -222,11 +234,11 @@ class GoogleSitemapTest extends FunctionalTest
         if (!class_exists('Page')) {
             $this->markTestIncomplete('No cms module installed, page related test skipped');
         }
-        
+
         $page = $this->objFromFixture('Page', 'Page1');
         $page->publish('Stage', 'Live');
         $page->flushCache();
-    
+
         $page2 = $this->objFromFixture('Page', 'Page2');
         $page2->publish('Stage', 'Live');
         $page2->flushCache();
@@ -234,29 +246,29 @@ class GoogleSitemapTest extends FunctionalTest
         $this->assertDOSContains(array(
             array('Title' => 'Testpage1'),
             array('Title' => 'Testpage2')
-        ), GoogleSitemap::get_items('SiteTree'), "There should be 2 pages in the sitemap after publishing");
-    
+        ), GoogleSitemap::get_items(SiteTree::class), "There should be 2 pages in the sitemap after publishing");
+
         // check if we make a page readonly that it is hidden
         $page2->CanViewType = 'LoggedInUsers';
         $page2->write();
         $page2->publish('Stage', 'Live');
-    
+
         $this->session()->inst_set('loggedInAs', null);
-        
+
         $this->assertDOSEquals(array(
             array('Title' => 'Testpage1')
-        ), GoogleSitemap::get_items('SiteTree'), "There should be only 1 page, other is logged in only");
+        ), GoogleSitemap::get_items(SiteTree::class), "There should be only 1 page, other is logged in only");
     }
-    
+
     public function testAccess()
     {
         Config::inst()->update('GoogleSitemap', 'enabled', true);
-        
+
         $response = $this->get('sitemap.xml');
 
         $this->assertEquals(200, $response->getStatusCode(), 'Sitemap returns a 200 success when enabled');
         $this->assertEquals('application/xml; charset="utf-8"', $response->getHeader('Content-Type'));
-        
+
         GoogleSitemap::register_dataobject("GoogleSitemapTest_DataObject");
         $response = $this->get('sitemap.xml/sitemap/GoogleSitemapTest_DataObject/1');
         $this->assertEquals(200, $response->getStatusCode(), 'Sitemap returns a 200 success when enabled');
@@ -264,14 +276,14 @@ class GoogleSitemapTest extends FunctionalTest
 
         Config::inst()->remove('GoogleSitemap', 'enabled');
         Config::inst()->update('GoogleSitemap', 'enabled', false);
-        
+
         $response = $this->get('sitemap.xml');
         $this->assertEquals(404, $response->getStatusCode(), 'Sitemap index returns a 404 when disabled');
 
         $response = $this->get('sitemap.xml/sitemap/GoogleSitemapTest_DataObject/1');
         $this->assertEquals(404, $response->getStatusCode(), 'Sitemap file returns a 404 when disabled');
     }
-    
+
     public function testDecoratorAddsFields()
     {
         if (!class_exists("Page")) {
@@ -279,21 +291,21 @@ class GoogleSitemapTest extends FunctionalTest
         }
 
         $page = $this->objFromFixture('Page', 'Page1');
-    
+
         $fields = $page->getSettingsFields();
         $tab = $fields->fieldByName('Root')->fieldByName('Settings')->fieldByName('GoogleSitemap');
-    
-        $this->assertInstanceOf('Tab', $tab);
-        $this->assertInstanceOf('DropdownField', $tab->fieldByName('Priority'));
-        $this->assertInstanceOf('LiteralField', $tab->fieldByName('GoogleSitemapIntro'));
+
+        $this->assertInstanceOf(Tab::class, $tab);
+        $this->assertInstanceOf(DropdownField::class, $tab->fieldByName('Priority'));
+        $this->assertInstanceOf(LiteralField::class, $tab->fieldByName('GoogleSitemapIntro'));
     }
-    
+
     public function testGetPriority()
     {
         if (!class_exists("Page")) {
             $this->markTestIncomplete('No cms module installed, page related test skipped');
         }
-        
+
         $page = $this->objFromFixture('Page', 'Page1');
 
         // invalid field doesn't break google
@@ -303,31 +315,31 @@ class GoogleSitemapTest extends FunctionalTest
         // custom value (set as string as db field is varchar)
         $page->Priority = '0.2';
         $this->assertEquals(0.2, $page->getGooglePriority());
-        
+
         // -1 indicates that we should not index this
         $page->Priority = -1;
         $this->assertFalse($page->getGooglePriority());
     }
-    
+
     public function testUnpublishedPage()
     {
-        if (!class_exists('SiteTree')) {
+        if (!class_exists(SiteTree::class)) {
             $this->markTestSkipped('Test skipped; CMS module required for testUnpublishedPage');
         }
-        
+
         $orphanedPage = new SiteTree();
         $orphanedPage->ParentID = 999999; // missing parent id
         $orphanedPage->write();
         $orphanedPage->publish("Stage", "Live");
-        
+
         $rootPage = new SiteTree();
         $rootPage->ParentID = 0;
         $rootPage->write();
         $rootPage->publish("Stage", "Live");
-        
+
         $oldMode = Versioned::get_reading_mode();
-        Versioned::reading_stage('Live');
-        
+        Versioned::set_reading_mode('Live');
+
         try {
             $this->assertEmpty($orphanedPage->hasPublishedParent());
             $this->assertEmpty($orphanedPage->canIncludeInGoogleSitemap());
@@ -348,8 +360,8 @@ class GoogleSitemapTest extends FunctionalTest
  */
 class GoogleSitemapTest_DataObject extends DataObject implements TestOnly
 {
-    
-    public static $db = array(
+
+    private static $db = array(
         'Priority' => 'Varchar(10)'
     );
 
@@ -371,7 +383,7 @@ class GoogleSitemapTest_DataObject extends DataObject implements TestOnly
 class GoogleSitemapTest_OtherDataObject extends DataObject implements TestOnly
 {
 
-    public static $db = array(
+    private static $db = array(
         'Priority' => 'Varchar(10)'
     );
 
diff --git a/tests/GoogleSitemapTest.yml b/tests/GoogleSitemapTest.yml
index 0c99170..577e68e 100644
--- a/tests/GoogleSitemapTest.yml
+++ b/tests/GoogleSitemapTest.yml
@@ -4,7 +4,7 @@ GoogleSitemapTest_DataObject:
     DataObjectTest2:
         Priority: 0.2
     UnindexedDataObject:
-    	Priority: -1
+      Priority: -1
 
 GoogleSitemapTest_OtherDataObject:
     OtherDataObjectTest2:
@@ -12,4 +12,4 @@ GoogleSitemapTest_OtherDataObject:
 
 GoogleSitemapTest_UnviewableDataObject:
     Unviewable1:
-        Priority: 0.4
\ No newline at end of file
+        Priority: 0.4
diff --git a/tests/NamespacedTestObject.php b/tests/NamespacedTestObject.php
index 957df2e..2f8ebd4 100644
--- a/tests/NamespacedTestObject.php
+++ b/tests/NamespacedTestObject.php
@@ -2,7 +2,9 @@
 
 namespace SilverStripe\GoogleSitemaps;
 
-use Director, DataObject, TestOnly;
+use SilverStripe\Control\Director;
+use SilverStripe\Dev\TestOnly;
+use SilverStripe\ORM\DataObject;
 
 /**
  * @package googlesitemaps
@@ -10,7 +12,6 @@ use Director, DataObject, TestOnly;
  */
 class Test_DataObject extends DataObject implements TestOnly
 {
-
     public static $db = array(
         'Priority' => 'Varchar(10)'
     );