diff --git a/core/modules/outside_in/js/off-canvas.es6.js b/core/modules/outside_in/js/off-canvas.es6.js
index 507c4fe3d2..99077ec98f 100644
--- a/core/modules/outside_in/js/off-canvas.es6.js
+++ b/core/modules/outside_in/js/off-canvas.es6.js
@@ -134,8 +134,8 @@
       $element.css({ height: 'auto' });
       const modalHeight = $container.height();
 
-      $offsets.each(($offset) => {
-        offset += $($offset).outerHeight();
+      $offsets.each((i, e) => {
+        offset += $(e).outerHeight();
       });
 
       // Take internal padding into account.
diff --git a/core/modules/outside_in/js/off-canvas.js b/core/modules/outside_in/js/off-canvas.js
index 54e4e54c50..b9ec223d12 100644
--- a/core/modules/outside_in/js/off-canvas.js
+++ b/core/modules/outside_in/js/off-canvas.js
@@ -10,6 +10,7 @@
     minDisplaceWidth: 768,
 
     $mainCanvasWrapper: $('[data-off-canvas-main-canvas]'),
+
     isOffCanvas: function isOffCanvas($element) {
       return $element.is('#drupal-off-canvas');
     },
@@ -54,8 +55,8 @@
       $element.css({ height: 'auto' });
       var modalHeight = $container.height();
 
-      $offsets.each(function ($offset) {
-        offset += $($offset).outerHeight();
+      $offsets.each(function (i, e) {
+        offset += $(e).outerHeight();
       });
 
       var scrollOffset = $element.outerHeight() - $element.height();