diff --git a/core/templates/dev/head/base_components/base_content_directive.html b/core/templates/dev/head/base_components/base_content_directive.html
index fde2df51d4ef..9d01cf062504 100644
--- a/core/templates/dev/head/base_components/base_content_directive.html
+++ b/core/templates/dev/head/base_components/base_content_directive.html
@@ -23,7 +23,7 @@
     </div>
 
     <div class="oppia-base-container"
-         ng-class="{'oppia-sidebar-menu-open': $crtl.isSidebarShown(), 'oppia-sidebar-menu-closed': !$crtl.isSidebarShown()}"
+         ng-class="{'oppia-sidebar-menu-open': $ctrl.isSidebarShown(), 'oppia-sidebar-menu-closed': !$ctrl.isSidebarShown()}"
          ng-swipe-left="$ctrl.closeSidebarOnSwipe()" ng-swipe-disable-mouse="false">
       <div class="oppia-content-container">
         <div id="wrapper">