diff --git a/extension.json b/extension.json
index a58a906c..b953977c 100644
--- a/extension.json
+++ b/extension.json
@@ -233,6 +233,7 @@
 			"scripts": "js/ext.uls.compactlinks.js",
 			"styles": "css/ext.uls.compactlinks.less",
 			"dependencies": [
+				"es5-shim",
 				"jquery.uls.compact",
 				"mediawiki.language",
 				"mediawiki.ui.button"
diff --git a/resources/js/ext.uls.compactlinks.js b/resources/js/ext.uls.compactlinks.js
index bb37ebc9..3b819cc7 100644
--- a/resources/js/ext.uls.compactlinks.js
+++ b/resources/js/ext.uls.compactlinks.js
@@ -59,7 +59,7 @@
 		init: function () {
 			var max = this.options.max;
 			this.interlanguageList = this.getInterlanguageList();
-			this.listSize = this.getListSize();
+			this.listSize = Object.keys( this.interlanguageList ).length;
 
 			if ( this.listSize <= max ) {
 				// Not enough languages to compact the list
@@ -319,15 +319,6 @@
 			return interlanguageList;
 		},
 
-		/**
-		 * Get the size of the interlanguage list
-		 */
-		getListSize: function () {
-			return $.map( this.interlanguageList, function ( item, languageCode ) {
-				return languageCode;
-			} ).length;
-		},
-
 		/**
 		 * Hide the original interlanguage list
 		 */