diff --git a/addons/website/static/src/scss/website.scss b/addons/website/static/src/scss/website.scss
index 52bfd84f0d5..6c04ea931ea 100644
--- a/addons/website/static/src/scss/website.scss
+++ b/addons/website/static/src/scss/website.scss
@@ -1068,6 +1068,13 @@ header {
                     // menu when the off-canvas menu is open.
                     display: none;
                 }
+                #top_menu {
+                    // This is useful because otherwise, the 'order-first' class
+                    // of the 'template_header_vertical' template puts the menu
+                    // behind the "backdrop" and it's no longer possible to
+                    // click on the menu links (only on Firefox).
+                    order: unset !important;
+                }
             }
         }
         &.collapsing #top_menu {