diff --git a/browser/themes/windows/browser.css b/browser/themes/windows/browser.css
index 0afd560bc878..87a5e8c1bdb5 100644
--- a/browser/themes/windows/browser.css
+++ b/browser/themes/windows/browser.css
@@ -91,8 +91,8 @@
 /* We want a 4px gap between the TabsToolbar and the toolbar-menubar when the
    toolbar-menu is displayed, and a 16px gap when it is not. 1px is taken care
    of by the (light) outer shadow of the tab, the remaining 3/15 are these margins. */
-#toolbar-menubar:not([autohide=true]) ~ #TabsToolbar,
-#toolbar-menubar[autohide=true]:not([inactive]) ~ #TabsToolbar {
+#toolbar-menubar:not([autohide=true]) ~ #TabsToolbar:not([inFullscreen]),
+#toolbar-menubar[autohide=true]:not([inactive]) ~ #TabsToolbar:not([inFullscreen]) {
   margin-top: 3px;
 }