diff --git a/src/Extensions/ArchiveRestoreAction.php b/src/Extensions/ArchiveRestoreAction.php
index a68f8d2..650894e 100644
--- a/src/Extensions/ArchiveRestoreAction.php
+++ b/src/Extensions/ArchiveRestoreAction.php
@@ -12,10 +12,13 @@
 use SilverStripe\ORM\ValidationResult;
 use SilverStripe\Versioned\RestoreAction;
 use SilverStripe\Versioned\Versioned;
+use SilverStripe\Versioned\VersionedGridFieldItemRequest;
 use SilverStripe\VersionedAdmin\ArchiveAdmin;
 
 /**
  * Adds a restore action to the item edit form of ArchiveAdmin
+ *
+ * @extends DataExtension<VersionedGridFieldItemRequest>
  */
 class ArchiveRestoreAction extends DataExtension
 {
diff --git a/src/Extensions/BlockArchiveExtension.php b/src/Extensions/BlockArchiveExtension.php
index 7c5429a..d839d25 100644
--- a/src/Extensions/BlockArchiveExtension.php
+++ b/src/Extensions/BlockArchiveExtension.php
@@ -12,6 +12,8 @@
 
 /**
  * Adds a archive view for Elemental blocks
+ *
+ * @extends DataExtension<BaseElement>
  */
 class BlockArchiveExtension extends DataExtension implements ArchiveViewProvider
 {
diff --git a/src/Extensions/FileArchiveExtension.php b/src/Extensions/FileArchiveExtension.php
index 8c212ec..cc102c6 100644
--- a/src/Extensions/FileArchiveExtension.php
+++ b/src/Extensions/FileArchiveExtension.php
@@ -15,6 +15,8 @@
 
 /**
  * Adds a archive view for Files
+ *
+ * @extends DataExtension<File>
  */
 class FileArchiveExtension extends DataExtension implements ArchiveViewProvider
 {
diff --git a/src/Extensions/SiteTreeArchiveExtension.php b/src/Extensions/SiteTreeArchiveExtension.php
index 1b34291..3debea3 100644
--- a/src/Extensions/SiteTreeArchiveExtension.php
+++ b/src/Extensions/SiteTreeArchiveExtension.php
@@ -12,6 +12,8 @@
 
 /**
  * Adds a archive view for Pages
+ *
+ * @extends DataExtension<SiteTree>
  */
 class SiteTreeArchiveExtension extends DataExtension implements ArchiveViewProvider
 {
diff --git a/src/Extensions/UsedOnTableExtension.php b/src/Extensions/UsedOnTableExtension.php
index 4aec3ca..7aa55a8 100644
--- a/src/Extensions/UsedOnTableExtension.php
+++ b/src/Extensions/UsedOnTableExtension.php
@@ -2,12 +2,15 @@
 
 namespace SilverStripe\VersionedAdmin\Extensions;
 
+use SilverStripe\Admin\Forms\UsedOnTable;
 use SilverStripe\Core\Extension;
 use SilverStripe\Versioned\ChangeSetItem;
 
+/**
+ * @extends Extension<UsedOnTable>
+ */
 class UsedOnTableExtension extends Extension
 {
-
     /**
      * @var array $excludedClasses
      */