diff --git a/browser/themes/windows/browser.css b/browser/themes/windows/browser.css
index 72269e182a..e15c57095f 100644
--- a/browser/themes/windows/browser.css
+++ b/browser/themes/windows/browser.css
@@ -3643,7 +3643,8 @@ toolbar[brighttext] #addonbar-closebutton {
 }
 
 /* ::::: splitmenu highlight style that imitates Windows 7 start menu ::::: */
-@media (-moz-windows-default-theme) {
+@media (-moz-os-version: windows-vista) and (-moz-windows-default-theme),
+       (-moz-os-version: windows-win7) and (-moz-windows-default-theme) {
   .splitmenu-menuitem,
   .splitmenu-menu {
     -moz-appearance: none;