diff --git a/app/Http/Middleware/Authenticate.php b/app/Http/Middleware/Authenticate.php
index 852bef8abf..1aaca6fe38 100644
--- a/app/Http/Middleware/Authenticate.php
+++ b/app/Http/Middleware/Authenticate.php
@@ -2,10 +2,12 @@
 
 namespace App\Http\Middleware;
 
+use App\Models\Account;
 use App\Models\Contact;
 use App\Models\Invitation;
 use App\Models\ProposalInvitation;
 use Auth;
+use Utils;
 use Closure;
 use Session;
 
@@ -99,7 +101,21 @@ class Authenticate
             if ($request->ajax()) {
                 return response('Unauthorized.', 401);
             } else {
-                return redirect()->guest($guard == 'client' ? '/client/login' : '/login');
+                if ($guard == 'client') {
+                    $url = '/client/login';
+                    if (Utils::isNinja()) {
+                        if ($account && Utils::getSubdomain() == 'app') {
+                            $url .= '?account_key=' . $account->account_key;
+                        }
+                    } else {
+                        if ($account && Account::count() > 1) {
+                            $url .= '?account_key=' . $account->account_key;
+                        }
+                    }
+                } else {
+                    $url = '/login';
+                }
+                return redirect()->guest($url);
             }
         }
 
diff --git a/app/Libraries/Utils.php b/app/Libraries/Utils.php
index 3de9318251..5dab8479b5 100644
--- a/app/Libraries/Utils.php
+++ b/app/Libraries/Utils.php
@@ -1003,8 +1003,12 @@ class Utils
         return $str;
     }
 
-    public static function getSubdomain($url)
+    public static function getSubdomain($url = false)
     {
+        if (! $url) {
+            $url = Request::server('HTTP_HOST');
+        }
+
         $parts = parse_url($url);
         $subdomain = '';