--- a/browser/themes/gnomestripe/browser/browser.css
+++ b/browser/themes/gnomestripe/browser/browser.css
@@ -1224,17 +1224,19 @@ tabpanels {
 /* Tabstrip close button */
 .tabs-closebutton {
   list-style-image: url("moz-icon://stock/gtk-close?size=menu");
   border: none;
   margin-bottom: 1px;
 }
 
 .tabs-closebutton > .toolbarbutton-icon {
-  margin: 0;
+  /* XXX Buttons have padding in widget/ that we don't want here but can't override with good CSS, so we must
+     use evil CSS to give the impression of smaller content */
+  margin: -2px;
 }
 
 /* Tabbrowser arrowscrollbox arrows */
 .tabbrowser-arrowscrollbox > .scrollbutton-up {
   -moz-appearance: tab-scroll-arrow-back;
   margin: 0px;
 }