diff --git a/repo/resources/Resources.php b/repo/resources/Resources.php
index e10a855135f..2d0c671cfc2 100644
--- a/repo/resources/Resources.php
+++ b/repo/resources/Resources.php
@@ -140,7 +140,7 @@
 			],
 			'dependencies' => [
 				'wikibase',
-				'mediawiki.Uri',
+				'web2017-polyfills',
 			],
 		],
 
@@ -235,7 +235,6 @@
 				'mediawiki.api',
 				'mediawiki.cookie',
 				'mediawiki.page.watch.ajax',
-				'mediawiki.Uri',
 				'mediawiki.user',
 				'mw.config.values.wbRepo',
 				'mw.config.values.wbDataTypes',
diff --git a/repo/resources/wikibase.entityPage.entityLoaded.js b/repo/resources/wikibase.entityPage.entityLoaded.js
index f073891ed78..bf321a06544 100644
--- a/repo/resources/wikibase.entityPage.entityLoaded.js
+++ b/repo/resources/wikibase.entityPage.entityLoaded.js
@@ -18,20 +18,20 @@
  * } );
  *
  * @example <caption>Convert to jQuery promise</caption>
- * var entityPromise = $.Deferred( function ( deferred ) {
+ * const entityPromise = $.Deferred( function ( deferred ) {
  *     mw.hook( 'wikibase.entityPage.entityLoaded' ).add( function ( entity ) {
  *         deferred.resolve( entity );
  *     } );
  * } ).promise();
  *
  * @example <caption>Convert to native promise</caption>
- * var entityPromise = new Promise( function ( resolve ) {
+ * const entityPromise = new Promise( function ( resolve ) {
  *     mw.hook( 'wikibase.entityPage.entityLoaded' ).add( function ( entity ) {
  *         resolve( entity );
  *     } );
  * } );
  */
-( function ( mwConfig, mwUri ) {
+( function ( mwConfig ) {
 	'use strict';
 
 	/**
@@ -42,11 +42,11 @@
 	 */
 	function deepFreeze( obj ) {
 		// Retrieve the property names defined on obj
-		var propNames = Object.getOwnPropertyNames( obj );
+		const propNames = Object.getOwnPropertyNames( obj );
 
 		// Freeze properties before freezing self
 		propNames.forEach( function ( name ) {
-			var prop = obj[ name ];
+			const prop = obj[ name ];
 
 			// Freeze prop if it is an object
 			if ( typeof prop === 'object' && prop !== null ) {
@@ -58,9 +58,7 @@
 		return Object.freeze( obj );
 	}
 
-	var entityId = mwConfig.get( 'wbEntityId' ),
-		url,
-		specialEntityDataPath;
+	const entityId = mwConfig.get( 'wbEntityId' );
 
 	if ( entityId === null ) {
 		mw.log.error(
@@ -71,19 +69,18 @@
 	}
 
 	// Load from Special:EntityData because it gets cached in several layers
-	specialEntityDataPath = mwConfig.get( 'wgArticlePath' ).replace(
+	const specialEntityDataPath = mwConfig.get( 'wgArticlePath' ).replace(
 		/\$1/g, 'Special:EntityData/' + entityId + '.json'
 	);
-	url = new mwUri( specialEntityDataPath );
-	url.extend( { revision: mwConfig.get( 'wgRevisionId' ) } );
-
-	$.getJSON( url.toString(), function ( data ) {
-		var wbEntity;
+	const url = new URL( specialEntityDataPath, location.href );
+	url.searchParams.set( 'revision', mwConfig.get( 'wgRevisionId' ) );
 
+	$.getJSON( url.toString(), ( data ) => {
 		if ( !data || !data.entities || !data.entities[ entityId ] ) {
 			return;
 		}
-		wbEntity = data.entities[ entityId ];
+
+		const wbEntity = data.entities[ entityId ];
 
 		if ( wbEntity ) {
 			// Note this assumes "wbEntity" contains valid JSON, and will throw an error otherwise.
@@ -91,4 +88,4 @@
 		}
 	} );
 
-}( mw.config, mw.Uri ) );
+}( mw.config ) );