diff --git a/includes/ApiCategoryTree.php b/includes/ApiCategoryTree.php
index 8b794e28..fcd367a1 100644
--- a/includes/ApiCategoryTree.php
+++ b/includes/ApiCategoryTree.php
@@ -2,14 +2,14 @@
 
 namespace MediaWiki\Extension\CategoryTree;
 
-use ApiBase;
-use ApiMain;
+use MediaWiki\Api\ApiBase;
+use MediaWiki\Api\ApiMain;
 use MediaWiki\Json\FormatJson;
 use MediaWiki\Languages\LanguageConverterFactory;
 use MediaWiki\Linker\LinkRenderer;
 use MediaWiki\MainConfigNames;
 use MediaWiki\Title\Title;
-use WANObjectCache;
+use Wikimedia\ObjectCache\WANObjectCache;
 use Wikimedia\ParamValidator\ParamValidator;
 use Wikimedia\Rdbms\IConnectionProvider;
 
diff --git a/includes/CategoryTree.php b/includes/CategoryTree.php
index 5aeaff9f..d814e4da 100644
--- a/includes/CategoryTree.php
+++ b/includes/CategoryTree.php
@@ -24,7 +24,6 @@
 
 namespace MediaWiki\Extension\CategoryTree;
 
-use ExtensionRegistry;
 use MediaWiki\Category\Category;
 use MediaWiki\Config\Config;
 use MediaWiki\Context\IContextSource;
@@ -35,6 +34,7 @@ use MediaWiki\Linker\LinkRenderer;
 use MediaWiki\MediaWikiServices;
 use MediaWiki\Output\OutputPage;
 use MediaWiki\Parser\Parser;
+use MediaWiki\Registration\ExtensionRegistry;
 use MediaWiki\SpecialPage\SpecialPage;
 use MediaWiki\Title\Title;
 use Wikimedia\Rdbms\IConnectionProvider;