diff --git a/userChrome.css b/userChrome.css
index 0921b24..922a4e9 100644
--- a/userChrome.css
+++ b/userChrome.css
@@ -26,7 +26,7 @@
       margin: 0 !important;
       border-radius: var(--tab-border-radius) !important;
       border-right: 2px solid var(--identity-stroke-color) !important;
-      background-color: unset !important;
+      background: unset !important;
     }
 
     /* Make the tab close button smaller */