diff --git a/modules/ext.categoryTree/ext.categoryTree.js b/modules/ext.categoryTree/ext.categoryTree.js
index ca7dc6cc..7a1b6b9e 100644
--- a/modules/ext.categoryTree/ext.categoryTree.js
+++ b/modules/ext.categoryTree/ext.categoryTree.js
@@ -22,177 +22,174 @@
  * @author Daniel Kinzler, brightbyte.de
  */
 
-( function () {
-	const config = require( './data.json' );
+const config = require( './data.json' );
 
-	/**
-	 * Expands a given node (loading it's children if not loaded)
-	 *
-	 * @param {jQuery} $link
-	 */
-	function expandNode( $link ) {
-		// Show the children node
-		const $children = $link.parents( '.CategoryTreeItem' )
-			.siblings( '.CategoryTreeChildren' )
-			.css( 'display', '' );
+/**
+ * Expands a given node (loading it's children if not loaded)
+ *
+ * @param {jQuery} $link
+ */
+function expandNode( $link ) {
+	// Show the children node
+	const $children = $link.parents( '.CategoryTreeItem' )
+		.siblings( '.CategoryTreeChildren' )
+		.css( 'display', '' );
 
-		$link.attr( {
-			title: mw.msg( 'categorytree-collapse' ),
-			'aria-expanded': 'true'
-		} );
-
-		if ( !$link.data( 'ct-loaded' ) ) {
-			loadChildren( $link, $children );
-		}
-	}
-
-	/**
-	 * Collapses a node
-	 *
-	 * @param {jQuery} $link
-	 */
-	function collapseNode( $link ) {
-		// Hide the children node
-		$link.parents( '.CategoryTreeItem' )
-			.siblings( '.CategoryTreeChildren' )
-			.css( 'display', 'none' );
-
-		$link.attr( {
-			title: mw.msg( 'categorytree-expand' ),
-			'aria-expanded': 'false'
-		} );
-	}
-
-	/**
-	 * Handles clicks on the expand buttons, and calls the appropriate function
-	 *
-	 * @param {jQuery.Event} e
-	 */
-	function handleNode( e ) {
-		e.preventDefault();
-
-		const $link = $( this );
-		if ( $link.attr( 'aria-expanded' ) === 'false' ) {
-			expandNode( $link );
-		} else {
-			collapseNode( $link );
-		}
-	}
-
-	/**
-	 * Attach click handler to buttons
-	 *
-	 * @param {jQuery} $content
-	 */
-	function attachHandler( $content ) {
-		$content.find( '.CategoryTreeToggle' )
-			.on( 'click', handleNode )
-			.attr( {
-				role: 'button',
-				title: function () {
-					return mw.msg(
-						$( this ).attr( 'aria-expanded' ) === 'false' ?
-							'categorytree-expand' :
-							'categorytree-collapse'
-					);
-				}
-			} )
-			.addClass( 'CategoryTreeToggleHandlerAttached' );
-	}
-
-	/**
-	 * Loads children for a node via an HTTP call
-	 *
-	 * @param {jQuery} $link
-	 * @param {jQuery} $children
-	 */
-	function loadChildren( $link, $children ) {
-		/**
-		 * Error callback
-		 */
-		function error() {
-			const $retryLink = $( '<a>' )
-				.text( mw.msg( 'categorytree-retry' ) )
-				.attr( {
-					role: 'button',
-					tabindex: 0
-				} )
-				.on( 'click keypress', ( e ) => {
-					if (
-						e.type === 'click' ||
-						e.type === 'keypress' && e.which === 13
-					) {
-						loadChildren( $link, $children );
-					}
-				} );
-
-			$children
-				.text( mw.msg( 'categorytree-error' ) + ' ' )
-				.append( $retryLink );
-		}
-
-		$link.data( 'ct-loaded', true );
-
-		$children.empty().append(
-			$( '<i>' )
-				.addClass( 'CategoryTreeNotice' )
-				.text( mw.msg( 'categorytree-loading' ) )
-		);
-
-		const $linkParentCTTag = $link.parents( '.CategoryTreeTag' );
-
-		// Element may not have a .CategoryTreeTag parent, fallback to defauls
-		// Probably a CategoryPage (@todo: based on what?)
-		const ctTitle = $link.attr( 'data-ct-title' );
-		const ctMode = $linkParentCTTag.data( 'ct-mode' );
-		const mode = typeof ctMode === 'number' ? ctMode : undefined;
-		const ctOptions = $linkParentCTTag.attr( 'data-ct-options' ) || config.defaultCtOptions;
-
-		// Mode and options have defaults or fallbacks, title does not.
-		// Don't make a request if there is no title.
-		if ( !ctTitle ) {
-			error();
-			return;
-		}
-
-		new mw.Api().get( {
-			action: 'categorytree',
-			category: ctTitle,
-			options: ctOptions,
-			uselang: mw.config.get( 'wgUserLanguage' ),
-			formatversion: 2
-		} ).done( ( data ) => {
-			data = data.categorytree.html;
-
-			let $data;
-			if ( data === '' ) {
-				$data = $( '<i>' ).addClass( 'CategoryTreeNotice' )
-					// eslint-disable-next-line mediawiki/msg-doc
-					.text( mw.msg( {
-						0: 'categorytree-no-subcategories',
-						10: 'categorytree-no-pages',
-						100: 'categorytree-no-parent-categories'
-					}[ mode ] || 'categorytree-nothing-found' ) );
-			} else {
-				$data = $( $.parseHTML( data ) );
-				attachHandler( $data );
-			}
-
-			$children.empty().append( $data );
-		} ).fail( error );
-	}
-
-	// Register click events
-	mw.hook( 'wikipage.content' ).add( attachHandler );
-
-	// Attach click handler for categories.
-	// This is needed when wgCategoryTreeHijackPageCategories is enabled.
-	mw.hook( 'wikipage.categories' ).add( attachHandler );
-
-	$( () => {
-		// Attach click handler for sidebar
-		// eslint-disable-next-line no-jquery/no-global-selector
-		attachHandler( $( '#p-categorytree-portlet' ) );
+	$link.attr( {
+		title: mw.msg( 'categorytree-collapse' ),
+		'aria-expanded': 'true'
 	} );
 
-}() );
+	if ( !$link.data( 'ct-loaded' ) ) {
+		loadChildren( $link, $children );
+	}
+}
+
+/**
+ * Collapses a node
+ *
+ * @param {jQuery} $link
+ */
+function collapseNode( $link ) {
+	// Hide the children node
+	$link.parents( '.CategoryTreeItem' )
+		.siblings( '.CategoryTreeChildren' )
+		.css( 'display', 'none' );
+
+	$link.attr( {
+		title: mw.msg( 'categorytree-expand' ),
+		'aria-expanded': 'false'
+	} );
+}
+
+/**
+ * Handles clicks on the expand buttons, and calls the appropriate function
+ *
+ * @param {jQuery.Event} e
+ */
+function handleNode( e ) {
+	e.preventDefault();
+
+	const $link = $( this );
+	if ( $link.attr( 'aria-expanded' ) === 'false' ) {
+		expandNode( $link );
+	} else {
+		collapseNode( $link );
+	}
+}
+
+/**
+ * Attach click handler to buttons
+ *
+ * @param {jQuery} $content
+ */
+function attachHandler( $content ) {
+	$content.find( '.CategoryTreeToggle' )
+		.on( 'click', handleNode )
+		.attr( {
+			role: 'button',
+			title: function () {
+				return mw.msg(
+					$( this ).attr( 'aria-expanded' ) === 'false' ?
+						'categorytree-expand' :
+						'categorytree-collapse'
+				);
+			}
+		} )
+		.addClass( 'CategoryTreeToggleHandlerAttached' );
+}
+
+/**
+ * Loads children for a node via an HTTP call
+ *
+ * @param {jQuery} $link
+ * @param {jQuery} $children
+ */
+function loadChildren( $link, $children ) {
+	/**
+	 * Error callback
+	 */
+	function error() {
+		const $retryLink = $( '<a>' )
+			.text( mw.msg( 'categorytree-retry' ) )
+			.attr( {
+				role: 'button',
+				tabindex: 0
+			} )
+			.on( 'click keypress', ( e ) => {
+				if (
+					e.type === 'click' ||
+					e.type === 'keypress' && e.which === 13
+				) {
+					loadChildren( $link, $children );
+				}
+			} );
+
+		$children
+			.text( mw.msg( 'categorytree-error' ) + ' ' )
+			.append( $retryLink );
+	}
+
+	$link.data( 'ct-loaded', true );
+
+	$children.empty().append(
+		$( '<i>' )
+			.addClass( 'CategoryTreeNotice' )
+			.text( mw.msg( 'categorytree-loading' ) )
+	);
+
+	const $linkParentCTTag = $link.parents( '.CategoryTreeTag' );
+
+	// Element may not have a .CategoryTreeTag parent, fallback to defauls
+	// Probably a CategoryPage (@todo: based on what?)
+	const ctTitle = $link.attr( 'data-ct-title' );
+	const ctMode = $linkParentCTTag.data( 'ct-mode' );
+	const mode = typeof ctMode === 'number' ? ctMode : undefined;
+	const ctOptions = $linkParentCTTag.attr( 'data-ct-options' ) || config.defaultCtOptions;
+
+	// Mode and options have defaults or fallbacks, title does not.
+	// Don't make a request if there is no title.
+	if ( !ctTitle ) {
+		error();
+		return;
+	}
+
+	new mw.Api().get( {
+		action: 'categorytree',
+		category: ctTitle,
+		options: ctOptions,
+		uselang: mw.config.get( 'wgUserLanguage' ),
+		formatversion: 2
+	} ).done( ( data ) => {
+		data = data.categorytree.html;
+
+		let $data;
+		if ( data === '' ) {
+			$data = $( '<i>' ).addClass( 'CategoryTreeNotice' )
+				// eslint-disable-next-line mediawiki/msg-doc
+				.text( mw.msg( {
+					0: 'categorytree-no-subcategories',
+					10: 'categorytree-no-pages',
+					100: 'categorytree-no-parent-categories'
+				}[ mode ] || 'categorytree-nothing-found' ) );
+		} else {
+			$data = $( $.parseHTML( data ) );
+			attachHandler( $data );
+		}
+
+		$children.empty().append( $data );
+	} ).fail( error );
+}
+
+// Register click events
+mw.hook( 'wikipage.content' ).add( attachHandler );
+
+// Attach click handler for categories.
+// This is needed when wgCategoryTreeHijackPageCategories is enabled.
+mw.hook( 'wikipage.categories' ).add( attachHandler );
+
+$( () => {
+	// Attach click handler for sidebar
+	// eslint-disable-next-line no-jquery/no-global-selector
+	attachHandler( $( '#p-categorytree-portlet' ) );
+} );