diff --git a/extension.json b/extension.json
index 774ce097..993663a0 100644
--- a/extension.json
+++ b/extension.json
@@ -100,13 +100,14 @@
 	},
 	"Hooks": {
 		"MediaWikiServices": "config",
-		"ArticleFromTitle": "default",
 		"SpecialTrackingCategories::preprocess": "default",
 		"SpecialTrackingCategories::generateCatLink": "default",
 		"SkinAfterPortlet": "default",
 		"SkinBuildSidebar": "default",
 		"ParserFirstCallInit": "default",
-		"OutputPageMakeCategoryLinks": "default"
+		"OutputPageMakeCategoryLinks": "default",
+		"CategoryViewer::doCategoryQuery": "default",
+		"CategoryViewer::generateLink": "default"
 	},
 	"config": {
 		"CategoryTreeMaxChildren": {
diff --git a/includes/CategoryCache.php b/includes/CategoryCache.php
index a54620f0..e9e93dfd 100644
--- a/includes/CategoryCache.php
+++ b/includes/CategoryCache.php
@@ -23,6 +23,7 @@ namespace MediaWiki\Extension\CategoryTree;
 use Category;
 use MediaWiki\Linker\LinkTarget;
 use Wikimedia\Rdbms\ILoadBalancer;
+use Wikimedia\Rdbms\IResultWrapper;
 
 /**
  * Caches Category::class objects
@@ -91,6 +92,13 @@ class CategoryCache {
 			->caller( __METHOD__ )
 			->fetchResultSet();
 
+		$this->fillFromQuery( $rows );
+	}
+
+	/**
+	 * @param IResultWrapper $rows
+	 */
+	public function fillFromQuery( IResultWrapper $rows ) {
 		foreach ( $rows as $row ) {
 			$this->cache[$row->cat_title] = Category::newFromRow( $row );
 		}
diff --git a/includes/CategoryTreeCategoryPage.php b/includes/CategoryTreeCategoryPage.php
deleted file mode 100644
index 60751184..00000000
--- a/includes/CategoryTreeCategoryPage.php
+++ /dev/null
@@ -1,28 +0,0 @@
-<?php
-/**
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
- * http://www.gnu.org/copyleft/gpl.html
- *
- * @file
- */
-
-namespace MediaWiki\Extension\CategoryTree;
-
-use CategoryPage;
-
-class CategoryTreeCategoryPage extends CategoryPage {
-	/** @var string */
-	public $mCategoryViewerClass = CategoryTreeCategoryViewer::class;
-}
diff --git a/includes/CategoryTreeCategoryViewer.php b/includes/CategoryTreeCategoryViewer.php
deleted file mode 100644
index 22cc265a..00000000
--- a/includes/CategoryTreeCategoryViewer.php
+++ /dev/null
@@ -1,70 +0,0 @@
-<?php
-/**
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
- * http://www.gnu.org/copyleft/gpl.html
- *
- * @file
- */
-
-namespace MediaWiki\Extension\CategoryTree;
-
-use Category;
-use CategoryViewer;
-
-class CategoryTreeCategoryViewer extends CategoryViewer {
-	/** @var CategoryTree */
-	public $categorytree;
-
-	/**
-	 * @return CategoryTree
-	 */
-	private function getCategoryTree() {
-		if ( !isset( $this->categorytree ) ) {
-			CategoryTree::setHeaders( $this->getOutput() );
-
-			$options = $this->getConfig()->get( 'CategoryTreeCategoryPageOptions' );
-
-			$mode = $this->getRequest()->getRawVal( 'mode' );
-			if ( $mode !== null ) {
-				$options['mode'] = CategoryTree::decodeMode( $mode );
-			}
-
-			$this->categorytree = new CategoryTree( $options );
-		}
-
-		return $this->categorytree;
-	}
-
-	/**
-	 * Add a subcategory to the internal lists
-	 * @param Category $cat
-	 * @param string $sortkey
-	 * @param int $pageLength
-	 */
-	public function addSubcategoryObject( Category $cat, $sortkey, $pageLength ) {
-		$title = $cat->getTitle();
-
-		if ( $this->getRequest()->getCheck( 'notree' ) ) {
-			parent::addSubcategoryObject( $cat, $sortkey, $pageLength );
-			return;
-		}
-
-		$tree = $this->getCategoryTree();
-
-		$this->children[] = $tree->renderNodeInfo( $title, $cat );
-
-		$this->children_start_char[] = $this->getSubcategorySortChar( $title, $sortkey );
-	}
-}
diff --git a/includes/Hooks.php b/includes/Hooks.php
index 68ca9ec7..4e441273 100644
--- a/includes/Hooks.php
+++ b/includes/Hooks.php
@@ -24,24 +24,25 @@
 
 namespace MediaWiki\Extension\CategoryTree;
 
-use Article;
 use Config;
 use Html;
-use IContextSource;
+use MediaWiki\Hook\CategoryViewer__doCategoryQueryHook;
+use MediaWiki\Hook\CategoryViewer__generateLinkHook;
 use MediaWiki\Hook\OutputPageMakeCategoryLinksHook;
 use MediaWiki\Hook\ParserFirstCallInitHook;
 use MediaWiki\Hook\SkinBuildSidebarHook;
 use MediaWiki\Hook\SpecialTrackingCategories__generateCatLinkHook;
 use MediaWiki\Hook\SpecialTrackingCategories__preprocessHook;
 use MediaWiki\Linker\LinkTarget;
-use MediaWiki\Page\Hook\ArticleFromTitleHook;
 use OutputPage;
 use Parser;
 use PPFrame;
+use RequestContext;
 use Sanitizer;
 use Skin;
 use SpecialPage;
 use Title;
+use Wikimedia\Rdbms\IResultWrapper;
 
 /**
  * Hooks for the CategoryTree extension, an AJAX based gadget
@@ -50,12 +51,13 @@ use Title;
  * @phpcs:disable MediaWiki.NamingConventions.LowerCamelFunctionsName.FunctionName
  */
 class Hooks implements
-	ArticleFromTitleHook,
 	SpecialTrackingCategories__preprocessHook,
 	SpecialTrackingCategories__generateCatLinkHook,
 	SkinBuildSidebarHook,
 	ParserFirstCallInitHook,
-	OutputPageMakeCategoryLinksHook
+	OutputPageMakeCategoryLinksHook,
+	CategoryViewer__doCategoryQueryHook,
+	CategoryViewer__generateLinkHook
 {
 
 	/** @var CategoryCache */
@@ -208,20 +210,6 @@ class Hooks implements
 		return $ct->getTag( $parser, $cat, $hideroot, $attr, $depth, $allowMissing );
 	}
 
-	/**
-	 * ArticleFromTitle hook, override category page handling
-	 *
-	 * @param Title $title
-	 * @param Article|null &$article Article (object) that will be returned
-	 * @param IContextSource $context
-	 * @return bool|void True or no return value to continue or false to abort
-	 */
-	public function onArticleFromTitle( $title, &$article, $context ) {
-		if ( $title->inNamespace( NS_CATEGORY ) ) {
-			$article = new CategoryTreeCategoryPage( $title );
-		}
-	}
-
 	/**
 	 * OutputPageMakeCategoryLinks hook, override category links
 	 * @param OutputPage $out
@@ -293,4 +281,45 @@ class Hooks implements
 
 		$html .= CategoryTree::createCountString( $specialPage->getContext(), $cat, 0 );
 	}
+
+	/**
+	 * @param string $type
+	 * @param IResultWrapper $res
+	 */
+	public function onCategoryViewer__doCategoryQuery( $type, $res ) {
+		if ( $type === 'subcat' && $res ) {
+			$this->categoryCache->fillFromQuery( $res );
+			CategoryTree::setHeaders( RequestContext::getMain()->getOutput() );
+		}
+	}
+
+	/**
+	 * @param string $type
+	 * @param Title $title
+	 * @param string $html
+	 * @param string &$link
+	 * @return bool
+	 */
+	public function onCategoryViewer__generateLink( $type, $title, $html, &$link ) {
+		if ( $type !== 'subcat' || $link !== null ) {
+			return true;
+		}
+
+		$request = RequestContext::getMain()->getRequest();
+		if ( $request->getCheck( 'notree' ) ) {
+			return true;
+		}
+
+		$options = $this->config->get( 'CategoryTreeCategoryPageOptions' );
+		$mode = $request->getRawVal( 'mode' );
+		if ( $mode !== null ) {
+			$options['mode'] = $mode;
+		}
+		$tree = new CategoryTree( $options );
+
+		$cat = $this->categoryCache->getCategory( $title );
+
+		$link = $tree->renderNodeInfo( $title, $cat );
+		return false;
+	}
 }