diff --git a/src/wp-admin/js/customize-widgets.js b/src/wp-admin/js/customize-widgets.js
index 1307655490..7859a6120a 100644
--- a/src/wp-admin/js/customize-widgets.js
+++ b/src/wp-admin/js/customize-widgets.js
@@ -259,7 +259,7 @@ var WidgetCustomizer = ( function ($) {
 
 						// Check if the widget is in another sidebar
 						wp.customize.each( function ( other_setting ) {
-							if ( other_setting.id === control.setting.id || 0 !== _.indexOf( other_setting.id, 'sidebars_widgets[' ) || other_setting.id === 'sidebars_widgets[wp_inactive_widgets]' ) {
+							if ( other_setting.id === control.setting.id || 0 !== other_setting.id.indexOf( 'sidebars_widgets[' ) || other_setting.id === 'sidebars_widgets[wp_inactive_widgets]' ) {
 								return;
 							}
 							var other_sidebar_widgets = other_setting(), i;
@@ -569,7 +569,7 @@ var WidgetCustomizer = ( function ($) {
 				if ( other_setting.id === control.setting.id ) {
 					return;
 				}
-				if ( 0 !== _.indexOf( other_setting.id, 'sidebars_widgets[' ) ) {
+				if ( 0 !== other_setting.id.indexOf( 'sidebars_widgets[' ) ) {
 					return;
 				}
 				var other_sidebar_widgets = other_setting().slice(), i;
@@ -760,7 +760,7 @@ var WidgetCustomizer = ( function ($) {
 
 			// Reposition whenever a sidebar's widgets are changed
 			wp.customize.each( function ( setting ) {
-				if ( 0 === _.indexOf( setting.id, 'sidebars_widgets[' ) ) {
+				if ( 0 === setting.id.indexOf( 'sidebars_widgets[' ) ) {
 					setting.bind( function () {
 						if ( control.container.hasClass( 'expanded' ) ) {
 							position_widget();