--- a/browser/themes/shared/toolbarbuttons.inc.css
+++ b/browser/themes/shared/toolbarbuttons.inc.css
@@ -14,17 +14,20 @@
 
   --backbutton-border-color: hsla(240,5%,5%,.3);
   /* This default value of --toolbarbutton-height is defined to prevent
      CSS errors for an invalid variable. The value should not get used,
      as a more specific value should be set when the value will be used. */
   --toolbarbutton-height: 0;
 }
 
-/* Larger buttons in touch mode */
+:root[uidensity=compact] {
+  --toolbarbutton-inner-padding: 5px;
+}
+
 :root[uidensity=touch] {
   --toolbarbutton-inner-padding: 9px;
 }
 
 toolbar[brighttext] {
   --toolbarbutton-hover-background: hsla(0,0%,100%,.2);
   --toolbarbutton-active-background: hsla(0,0%,100%,.3);