diff --git a/firefox/userChrome.css b/firefox/userChrome.css
index 9baec3f..d689af2 100644
--- a/firefox/userChrome.css
+++ b/firefox/userChrome.css
@@ -1,7 +1,17 @@
+/* Border Radius */
+
 * {
   border-radius: 0 !important;
 }
 
+:root {
+  --tab-border-radius: 0 !important;
+}
+
+menupopup, panel {
+  --panel-border-radius: 0 !important;
+}
+
 /* Tabbar */
 
 #main-window[tabsintitlebar="true"]:not([extradragspace="true"]) #TabsToolbar {