diff --git a/_config.php b/_config.php
index e7bd2ee..237dd1a 100644
--- a/_config.php
+++ b/_config.php
@@ -1,6 +1,8 @@
 <?php
 
 use SilverStripe\ORM\DB;
+use SilverStripe\Core\Injector\Injector;
+
 
 // Determine whether there is a testsession currently running, and if so - setup the persistent details for it.
 Injector::inst()->get('TestSessionEnvironment')->loadFromFile();
diff --git a/code/TestSessionController.php b/code/TestSessionController.php
index 75fbd9d..4191482 100644
--- a/code/TestSessionController.php
+++ b/code/TestSessionController.php
@@ -1,8 +1,27 @@
 <?php
 
-use SilverStripe\ORM\DB;
+use SilverStripe\Control\Controller;
+use SilverStripe\Control\Director;
+use SilverStripe\Control\Session;
+use SilverStripe\Control\SS_HTTPRequest;
+use SilverStripe\Core\Injector\Injector;
+use SilverStripe\Dev\Deprecation;
+use SilverStripe\Dev\SapphireTest;
+use SilverStripe\Forms\CheckboxField;
+use SilverStripe\Forms\DatetimeField;
+use SilverStripe\Forms\DropdownField;
+use SilverStripe\Forms\FieldList;
+use SilverStripe\Forms\Form;
+use SilverStripe\Forms\FormAction;
+use SilverStripe\Forms\HiddenField;
+use SilverStripe\Forms\TextField;
 use SilverStripe\ORM\ArrayList;
+use SilverStripe\ORM\DB;
 use SilverStripe\ORM\FieldType\DBHTMLText;
+use SilverStripe\Security\Permission;
+use SilverStripe\Security\Security;
+use SilverStripe\View\ArrayData;
+use SilverStripe\View\Requirements;
 
 /**
  * Requires PHP's mycrypt extension in order to set the database name as an encrypted cookie.
@@ -51,7 +70,8 @@ class TestSessionController extends Controller
             && (Director::isDev() || Director::isTest() || Director::is_cli() || Permission::check("ADMIN"))
         );
         if (!$canAccess) {
-            return Security::permissionFailure($this);
+            Security::permissionFailure($this);
+            return;
         }
 
         Requirements::javascript('framework/thirdparty/jquery/jquery.js');
@@ -84,7 +104,7 @@ class TestSessionController extends Controller
         if (!empty($params['globalTestSession'])) {
             $id = null;
         } else {
-            $generator = Injector::inst()->get('RandomGenerator');
+            $generator = Injector::inst()->get('SilverStripe\\Security\\RandomGenerator');
             $id = substr($generator->randomToken(), 0, 10);
             Session::set('TestSessionId', $id);
         }
diff --git a/code/TestSessionEnvironment.php b/code/TestSessionEnvironment.php
index e49ed15..062844b 100644
--- a/code/TestSessionEnvironment.php
+++ b/code/TestSessionEnvironment.php
@@ -1,9 +1,16 @@
 <?php
 
+use SilverStripe\Control\Director;
+use SilverStripe\Control\Session;
+use SilverStripe\Core\Injector\Injector;
+use SilverStripe\Core\Object;
+use SilverStripe\Dev\FixtureFactory;
+use SilverStripe\Dev\SapphireTest;
 use SilverStripe\ORM\DB;
 use SilverStripe\ORM\DatabaseAdmin;
 use SilverStripe\ORM\Versioning\Versioned;
 
+
 /**
  * Responsible for starting and finalizing test sessions.
  * Since these session span across multiple requests, session information is persisted
@@ -120,6 +127,7 @@ class TestSessionEnvironment extends Object
      * onBeforeApplyState() and onAfterApplyState(). See the {@link self::applyState()} method for more.
      *
      * @param array $state An array of test state options to write.
+     * @param mixed $id
      */
     public function startTestSession($state = null, $id = null)
     {
@@ -163,6 +171,7 @@ class TestSessionEnvironment extends Object
      * You can extend this by creating an Extension object and implementing either onBeforeApplyState() or
      * onAfterApplyState() to add your own test state handling in.
      *
+     * @param mixed $state
      * @throws LogicException
      * @throws InvalidArgumentException
      */
@@ -170,8 +179,6 @@ class TestSessionEnvironment extends Object
     {
         $this->extend('onBeforeApplyState', $state);
 
-        $database = (isset($state->database)) ? $state->database : null;
-
         // back up source
         global $databaseConfig;
         $this->oldDatabaseName = $databaseConfig['database'];
@@ -244,7 +251,7 @@ class TestSessionEnvironment extends Object
         $mailer = (isset($state->mailer)) ? $state->mailer : null;
 
         if ($mailer) {
-            if (!class_exists($mailer) || !is_subclass_of($mailer, 'Mailer')) {
+            if (!class_exists($mailer) || !is_subclass_of($mailer, 'SilverStripe\\Control\\Email\\Mailer')) {
                 throw new InvalidArgumentException(sprintf(
                     'Class "%s" is not a valid class, or subclass of Mailer',
                     $mailer
@@ -272,7 +279,7 @@ class TestSessionEnvironment extends Object
      * Import the database
      *
      * @param String $path Absolute path to a SQL dump (include DROP TABLE commands)
-     * @return void
+     * @param bool $requireDefaultRecords
      */
     public function importDatabase($path, $requireDefaultRecords = false)
     {
@@ -309,6 +316,8 @@ class TestSessionEnvironment extends Object
     /**
      * Sliented as if the file already exists by another process, we don't want
      * to modify.
+     *
+     * @param mixed $state
      */
     public function saveState($state)
     {
@@ -367,11 +376,11 @@ class TestSessionEnvironment extends Object
 
         if (SapphireTest::using_temp_db()) {
             $state = $this->getState();
-            $dbConn = DB::getConn();
+            $dbConn = DB::get_schema();
             $dbExists = $dbConn->databaseExists($state->database);
             if($dbExists) {
                 // Clean up temp database
-                $dbConn->dropDatabase();
+                $dbConn->dropDatabase($state->database);
                 file_put_contents('php://stdout', "Deleted temp database: $state->database" . PHP_EOL);
             }
             // End test session mode
@@ -406,8 +415,8 @@ class TestSessionEnvironment extends Object
             throw new LogicException("Fixture file must be inside the tests subfolder of one of your modules.");
         }
 
-        $factory = Injector::inst()->create('FixtureFactory');
-        $fixture = Injector::inst()->create('YamlFixture', $fixtureFile);
+        $factory = Injector::inst()->create('SilverStripe\\Dev\\FixtureFactory');
+        $fixture = Injector::inst()->create('SilverStripe\\Dev\\YamlFixture', $fixtureFile);
         $fixture->writeInto($factory);
 
         $state = $this->getState();
diff --git a/code/TestSessionRequestFilter.php b/code/TestSessionRequestFilter.php
index 8e78feb..88fd748 100644
--- a/code/TestSessionRequestFilter.php
+++ b/code/TestSessionRequestFilter.php
@@ -3,6 +3,14 @@
 use SilverStripe\ORM\DataModel;
 use SilverStripe\ORM\FieldType\DBDatetime;
 use SilverStripe\ORM\DB;
+use SilverStripe\Core\Injector\Injector;
+use SilverStripe\Control\SS_HTTPRequest;
+use SilverStripe\Control\Session;
+use SilverStripe\Core\Config\Config;
+use SilverStripe\Control\Director;
+use SilverStripe\Control\SS_HTTPResponse;
+use SilverStripe\Control\RequestFilter;
+
 
 /**
  * Sets state previously initialized through {@link TestSessionController}.
@@ -36,8 +44,8 @@ class TestSessionRequestFilter implements RequestFilter
         // Register mailer
         if (isset($testState->mailer)) {
             $mailer = $testState->mailer;
-            Injector::inst()->registerService(new $mailer(), 'Mailer');
-            Config::inst()->update("Email", "send_all_emails_to", null);
+            Injector::inst()->registerService(new $mailer(), 'SilverStripe\\Control\\Email\\Mailer');
+            Config::inst()->update("SilverStripe\\Control\\Email\\Email", "send_all_emails_to", null);
         }
 
         // Allows inclusion of a PHP file, usually with procedural commands
diff --git a/tests/unit/TestSessionStubCodeWriterTest.php b/tests/unit/TestSessionStubCodeWriterTest.php
index 727ff0a..4f2a982 100644
--- a/tests/unit/TestSessionStubCodeWriterTest.php
+++ b/tests/unit/TestSessionStubCodeWriterTest.php
@@ -1,4 +1,7 @@
 <?php
+
+use SilverStripe\Dev\SapphireTest;
+
 class TestSessionStubCodeWriterTest extends SapphireTest
 {