diff --git a/xpfe/appshell/nsAppShellService.cpp b/xpfe/appshell/nsAppShellService.cpp
index c9f987ad63b0..81511bfd9d5c 100644
--- a/xpfe/appshell/nsAppShellService.cpp
+++ b/xpfe/appshell/nsAppShellService.cpp
@@ -671,22 +671,21 @@ nsresult nsAppShellService::JustCreateTopWindow(
 
   widgetInitData.mRTL = LocaleService::GetInstance()->IsAppLocaleRTL();
 
-  nsresult rv =
-      window->Initialize(parent, center ? aParent : nullptr, aInitialWidth,
-                         aInitialHeight, aIsHiddenWindow, widgetInitData);
-
-  NS_ENSURE_SUCCESS(rv, rv);
-
   // Enforce the Private Browsing autoStart pref first.
   bool isPrivateBrowsingWindow =
       StaticPrefs::browser_privatebrowsing_autostart();
-
   if (aChromeMask & nsIWebBrowserChrome::CHROME_PRIVATE_WINDOW) {
     // Caller requested a private window
     isPrivateBrowsingWindow = true;
   }
   widgetInitData.mIsPrivate = isPrivateBrowsingWindow;
 
+  nsresult rv =
+      window->Initialize(parent, center ? aParent : nullptr, aInitialWidth,
+                         aInitialHeight, aIsHiddenWindow, widgetInitData);
+
+  NS_ENSURE_SUCCESS(rv, rv);
+
   nsCOMPtr<mozIDOMWindowProxy> domWin = do_GetInterface(aParent);
   nsCOMPtr<nsIWebNavigation> webNav = do_GetInterface(domWin);
   nsCOMPtr<nsILoadContext> parentContext = do_QueryInterface(webNav);