diff --git a/app/Http/Middleware/PreventAccessFromTenantDomains.php b/app/Http/Middleware/PreventAccessFromTenantDomains.php
new file mode 100644
index 0000000..ebf6f09
--- /dev/null
+++ b/app/Http/Middleware/PreventAccessFromTenantDomains.php
@@ -0,0 +1,20 @@
+<?php
+
+namespace App\Http\Middleware;
+
+use Closure;
+use Illuminate\Http\Request;
+use Stancl\Tenancy\Tenancy;
+
+class PreventAccessFromTenantDomains
+{
+    public function handle(Request $request, Closure $next)
+    {
+        // 如果租戶已初始化 (代表是從租戶域名存取)，則禁止訪問 Landlord 路由
+        if (tenancy()->initialized) {
+            abort(404);
+        }
+
+        return $next($request);
+    }
+}
diff --git a/routes/landlord.php b/routes/landlord.php
index ff21691..45f2b41 100644
--- a/routes/landlord.php
+++ b/routes/landlord.php
@@ -14,7 +14,7 @@ use App\Http\Controllers\Landlord\TenantController;
 |
 */
 
-Route::prefix('landlord')->name('landlord.')->middleware(['web', 'auth', \Stancl\Tenancy\Middleware\PreventAccessFromTenantDomains::class])->group(function () {
+Route::prefix('landlord')->name('landlord.')->middleware(['web', 'auth', \App\Http\Middleware\PreventAccessFromTenantDomains::class])->group(function () {
     // 房東儀表板
     Route::get('/', [DashboardController::class, 'index'])->name('dashboard');