diff --git a/browser/themes/linux/browser.css b/browser/themes/linux/browser.css
index a9276a678f16a67e2a003474203c37cb5c9300ad..892c69950d2a695b890fec9f8ea3f6e64032fe25 100644
--- a/browser/themes/linux/browser.css
+++ b/browser/themes/linux/browser.css
@@ -42,15 +42,17 @@
     -moz-default-appearance: -moz-window-decorations;
     appearance: auto;
 
-    #navigator-toolbox,
-    dialog::backdrop {
+    #zen-main-app-wrapper,
+    dialog::backdrop,
+    #browser::after,
+    #browser::before {
       border-top-left-radius: env(-moz-gtk-csd-titlebar-radius);
       border-top-right-radius: env(-moz-gtk-csd-titlebar-radius);
     }
 
     /* stylelint-disable-next-line media-query-no-invalid */
     @media (-moz-bool-pref: "widget.gtk.rounded-bottom-corners.enabled") {
-      #navigator-toolbox {
+      #zen-main-app-wrapper {
         /* The body clip below covers this. */
         border-radius: 0;
       }