diff --git a/browser/base/content/browser-tabsintitlebar.js b/browser/base/content/browser-tabsintitlebar.js
index ee78f05afda0..d4b8e367b69c 100644
--- a/browser/base/content/browser-tabsintitlebar.js
+++ b/browser/base/content/browser-tabsintitlebar.js
@@ -178,7 +178,7 @@ var TabsInTitlebar = {
 
       if (AppConstants.MOZ_PHOTON_THEME &&
           AppConstants.isPlatformAndVersionAtLeast("win", "10.0")) {
-        if (!menuHeight) {
+        if (!menuHeight && window.windowState == window.STATE_MAXIMIZED) {
           titlebarContentHeight = Math.max(titlebarContentHeight, fullTabsHeight);
           $("titlebar-buttonbox").style.height = titlebarContentHeight + "px";
         } else {