try #5085 @1.5

diff --git a/js/libs/fluidbook/fluidbook.nav.js b/js/libs/fluidbook/fluidbook.nav.js
index 06306006239c34b12fd980925d5d5ab57072587c..b2aad6528d28d3d96abe915c3098dcd96ba45cbc 100644 (file)
--- a/js/libs/fluidbook/fluidbook.nav.js
+++ b/js/libs/fluidbook/fluidbook.nav.js
@@ -68,6 +68,7 @@ FluidbookNav.prototype = {
         // Bind API hooks (see http://mmenu.frebsite.nl/documentation/core/off-canvas.html#h4)
         this.menuAPI.bind("open:finish", function () {
             $('body').addClass('menu-open');
+            $("nav#menu").addClass('mm-menu_opened');
             $this.menuIsOpen = true;
 
             setInterval(function () {