diff --git a/src/other/firefox/WhiteSur/parts/tabsbar.css b/src/other/firefox/WhiteSur/parts/tabsbar.css
index 9bfab7b..2001a4d 100644
--- a/src/other/firefox/WhiteSur/parts/tabsbar.css
+++ b/src/other/firefox/WhiteSur/parts/tabsbar.css
@@ -343,7 +343,7 @@ tab[selected]:-moz-window-inactive {
 
 .tab-background {
 	background-color: transparent !important;
-	transition: all 200ms;
+	transition: background-color 200ms;
 }
 
 .tab-background, .tab-stack {