diff --git a/_config.php b/_config.php
deleted file mode 100644
index a3682d6a..00000000
--- a/_config.php
+++ /dev/null
@@ -1,5 +0,0 @@
-<?php
-
-use SilverStripe\Dev\Deprecation;
-
-Deprecation::notification_version('2.0', 'subsites');
diff --git a/_config/middleware.yml b/_config/middleware.yml
index a6006a34..38440280 100644
--- a/_config/middleware.yml
+++ b/_config/middleware.yml
@@ -8,5 +8,3 @@ SilverStripe\Core\Injector\Injector:
     properties:
       Middlewares:
         SubsitesStateMiddleware: '%$SilverStripe\Subsites\Middleware\InitStateMiddleware'
-  SilverStripe\Dev\Tasks\MigrateFileTask:
-    class: SilverStripe\Subsites\Tasks\SubsiteMigrateFileTask
diff --git a/composer.json b/composer.json
index 77e0854b..01b8067e 100644
--- a/composer.json
+++ b/composer.json
@@ -15,17 +15,17 @@
         }
     ],
     "require": {
-        "php": "^7.4 || ^8.0",
-        "silverstripe/framework": "^4.10",
-        "silverstripe/cms": "^4.4@dev",
-        "silverstripe/admin": "^1.4@dev",
-        "silverstripe/asset-admin": "^1.4@dev",
-        "silverstripe/errorpage": "^1.4@dev",
-        "silverstripe/versioned": "^1.4@dev"
+        "php": "^8.1",
+        "silverstripe/framework": "^5",
+        "silverstripe/cms": "^5",
+        "silverstripe/admin": "^2",
+        "silverstripe/asset-admin": "^2",
+        "silverstripe/errorpage": "^2",
+        "silverstripe/versioned": "^2"
     },
     "require-dev": {
         "phpunit/phpunit": "^9.5",
-        "squizlabs/php_codesniffer": "^3.0"
+        "squizlabs/php_codesniffer": "^3"
     },
     "autoload": {
         "psr-4": {
diff --git a/src/Controller/SubsiteXHRController.php b/src/Controller/SubsiteXHRController.php
index c758d53b..4a52264c 100644
--- a/src/Controller/SubsiteXHRController.php
+++ b/src/Controller/SubsiteXHRController.php
@@ -3,6 +3,7 @@
 namespace SilverStripe\Subsites\Controller;
 
 use SilverStripe\Admin\LeftAndMain;
+use SilverStripe\Control\PjaxResponseNegotiator;
 use SilverStripe\Security\Member;
 use SilverStripe\Security\Permission;
 use SilverStripe\Subsites\Model\Subsite;
@@ -46,7 +47,7 @@ public function canAccess()
         ]);
     }
 
-    public function getResponseNegotiator()
+    public function getResponseNegotiator(): PjaxResponseNegotiator
     {
         $negotiator = parent::getResponseNegotiator();
 
diff --git a/src/Model/Subsite.php b/src/Model/Subsite.php
index 25ec6204..0e8ada54 100644
--- a/src/Model/Subsite.php
+++ b/src/Model/Subsite.php
@@ -971,11 +971,8 @@ public function getMembersByPermission($permissionCodes = ['ADMIN'])
 
     /**
      * Duplicate this subsite
-     * @param bool $doWrite
-     * @param string $manyMany
-     * @return DataObject
      */
-    public function duplicate($doWrite = true, $manyMany = 'many_many')
+    public function duplicate(bool $doWrite = true, ?array $manyMany = null): static
     {
         $duplicate = parent::duplicate($doWrite);
 
diff --git a/src/Tasks/SubsiteMigrateFileTask.php b/src/Tasks/SubsiteMigrateFileTask.php
deleted file mode 100644
index c00c7764..00000000
--- a/src/Tasks/SubsiteMigrateFileTask.php
+++ /dev/null
@@ -1,19 +0,0 @@
-<?php
-
-namespace SilverStripe\Subsites\Tasks;
-
-use SilverStripe\Dev\Tasks\MigrateFileTask;
-use SilverStripe\Subsites\Model\Subsite;
-
-class SubsiteMigrateFileTask extends MigrateFileTask
-{
-    public function run($request)
-    {
-        $origDisableSubsiteFilter = Subsite::$disable_subsite_filter;
-        Subsite::disable_subsite_filter(true);
-
-        parent::run($request);
-
-        Subsite::disable_subsite_filter($origDisableSubsiteFilter);
-    }
-}
diff --git a/tests/behat/features/insert-content-link.feature b/tests/behat/features/insert-content-link.feature
index 5b7f5926..9ac35e94 100644
--- a/tests/behat/features/insert-content-link.feature
+++ b/tests/behat/features/insert-content-link.feature
@@ -17,12 +17,12 @@ Feature: Insert an internal link into content
     # See "insert-a-link.feature" from silverstripe/cms
     When I select "My page" in the "Content" HTML field
     And I press the "Insert link" HTML field button
-    And I click "Page on this site" in the ".mce-menu" element
+    And I click "Page on this site" in the ".tox-collection__group" element
     Then I should see an "form#Form_editorInternalLink" element
-    When I click "(Search or choose Page)" in the ".Select-multi-value-wrapper" element
+    When I click on the ".treedropdownfield" element
     And I click "Another page" in the ".treedropdownfield__menu" element
     And I fill in "my desc" for "Link description"
-    And I press the "Insert" button
+    And I click on the "#Form_editorInternalLink_action_insert" element
     Then the "Content" HTML field should contain "<a title="my desc" href="[sitetree_link"
     And the "Content" HTML field should contain "My page</a>"
     # Required to avoid "unsaved changes" browser dialog
diff --git a/tests/php/SubsitesVirtualPageTest.php b/tests/php/SubsitesVirtualPageTest.php
index 140213e4..bc00cd24 100644
--- a/tests/php/SubsitesVirtualPageTest.php
+++ b/tests/php/SubsitesVirtualPageTest.php
@@ -5,7 +5,7 @@
 use Page;
 use SilverStripe\Assets\File;
 use SilverStripe\Assets\Filesystem;
-use SilverStripe\Assets\Tests\Storage\AssetStoreTest\TestAssetStore;
+use SilverStripe\Assets\Dev\TestAssetStore;
 use SilverStripe\CMS\Model\SiteTree;
 use SilverStripe\Control\Director;
 use SilverStripe\Core\Config\Config;