diff --git a/app/assets/stylesheets/layout/_main_menu.sass b/app/assets/stylesheets/layout/_main_menu.sass
index 10cd6e1953..9d399595ed 100644
--- a/app/assets/stylesheets/layout/_main_menu.sass
+++ b/app/assets/stylesheets/layout/_main_menu.sass
@@ -45,13 +45,6 @@ $menu-item-line-height: 30px
 
   @include varprop(background-color, main-menu-bg-color)
 
-  @-moz-document url-prefix()
-    #menu-sidebar
-      margin-right: -20px !important
-      margin-bottom: -20px !important
-      overflow-y: scroll
-      overflow-x: hidden
-
   #menu-sidebar
     height: 100%
     overflow: auto