diff --git a/code/Controller/AssetAdminFile.php b/code/Controller/AssetAdminFile.php
index 278ad5fb8..b85294612 100644
--- a/code/Controller/AssetAdminFile.php
+++ b/code/Controller/AssetAdminFile.php
@@ -7,17 +7,17 @@
 use SilverStripe\Assets\Shortcodes\FileLink;
 use SilverStripe\Control\Director;
 use SilverStripe\ORM\ArrayList;
-use SilverStripe\ORM\DataExtension;
 use SilverStripe\ORM\SS_List;
 use SilverStripe\Versioned\Versioned;
 use SilverStripe\Versioned\DataDifferencer;
+use SilverStripe\Core\Extension;
 
 /**
  * Update File dataobjects to be editable in this asset admin
  *
- * @extends DataExtension<File>
+ * @extends Extension<File>
  */
-class AssetAdminFile extends DataExtension
+class AssetAdminFile extends Extension
 {
     /**
      * Max width for inserted images
diff --git a/tests/php/Controller/AssetAdminTest/FileExtension.php b/tests/php/Controller/AssetAdminTest/FileExtension.php
index 0bab0c23d..99ef43608 100644
--- a/tests/php/Controller/AssetAdminTest/FileExtension.php
+++ b/tests/php/Controller/AssetAdminTest/FileExtension.php
@@ -3,9 +3,9 @@
 namespace SilverStripe\AssetAdmin\Tests\Controller\AssetAdminTest;
 
 use SilverStripe\Dev\TestOnly;
-use SilverStripe\ORM\DataExtension;
+use SilverStripe\Core\Extension;
 
-class FileExtension extends DataExtension implements TestOnly
+class FileExtension extends Extension implements TestOnly
 {
     protected function canView($member = null)
     {
diff --git a/tests/php/Controller/AssetAdminTest/FolderExtension.php b/tests/php/Controller/AssetAdminTest/FolderExtension.php
index 7e3713454..a8e7599b9 100644
--- a/tests/php/Controller/AssetAdminTest/FolderExtension.php
+++ b/tests/php/Controller/AssetAdminTest/FolderExtension.php
@@ -3,9 +3,9 @@
 namespace SilverStripe\AssetAdmin\Tests\Controller\AssetAdminTest;
 
 use SilverStripe\Dev\TestOnly;
-use SilverStripe\ORM\DataExtension;
+use SilverStripe\Core\Extension;
 
-class FolderExtension extends DataExtension implements TestOnly
+class FolderExtension extends Extension implements TestOnly
 {
     protected function canView($member = null, $context = array())
     {
diff --git a/tests/php/Forms/FileFormBuilderTest/FileExtension.php b/tests/php/Forms/FileFormBuilderTest/FileExtension.php
index e7e9799d7..f9fc09d53 100644
--- a/tests/php/Forms/FileFormBuilderTest/FileExtension.php
+++ b/tests/php/Forms/FileFormBuilderTest/FileExtension.php
@@ -3,13 +3,13 @@
 namespace SilverStripe\AssetAdmin\Tests\Forms\FileFormBuilderTest;
 
 use SilverStripe\Dev\TestOnly;
-use SilverStripe\ORM\DataExtension;
+use SilverStripe\Core\Extension;
 
 /**
  * An extension to test file permissions
  * @package SilverStripe\AssetAdmin\Tests\Forms\FileFormBuilderTest
  */
-class FileExtension extends DataExtension implements TestOnly
+class FileExtension extends Extension implements TestOnly
 {
     // public flags to toggle permissions during tests
     public static $canDelete = false;