diff --git a/src/TestSessionEnvironment.php b/src/TestSessionEnvironment.php
index 3a15f3c..17b49ba 100644
--- a/src/TestSessionEnvironment.php
+++ b/src/TestSessionEnvironment.php
@@ -86,10 +86,10 @@ class TestSessionEnvironment
     public function init(HTTPRequest $request)
     {
         if (!$this->id) {
-            $request->getSession()->start();
+            $request->getSession()->init();
             // $_SESSION != Session::get() in some execution paths, suspect Controller->pushCurrent()
             // as part of the issue, easiest resolution is to use session directly for now
-            $this->id = (isset($_SESSION['TestSessionId'])) ? $_SESSION['TestSessionId'] : null;
+            $this->id = $request->getSession()->get('TestSessionId');
         }
     }
 
diff --git a/src/TestSessionRequestFilter.php b/src/TestSessionRequestFilter.php
index fe48628..7999aaf 100644
--- a/src/TestSessionRequestFilter.php
+++ b/src/TestSessionRequestFilter.php
@@ -8,7 +8,6 @@ use SilverStripe\Control\Email\Mailer;
 use SilverStripe\Control\HTTPRequest;
 use SilverStripe\Control\HTTPResponse;
 use SilverStripe\Control\RequestFilter;
-use SilverStripe\Control\Session;
 use SilverStripe\Core\Injector\Injector;
 use SilverStripe\ORM\DB;
 use SilverStripe\ORM\FieldType\DBDatetime;
@@ -76,7 +75,7 @@ class TestSessionRequestFilter implements RequestFilter
 
         // Store PHP session
         $state = $this->testSessionEnvironment->getState();
-        $state->session = Session::get_all();
+        $state->session = $request->getSession()->getAll();
         $this->testSessionEnvironment->applyState($state);
     }
 }