diff --git a/app/Domains/Cart/Models/Cart.php b/app/Domains/Cart/Models/Cart.php
index a9d6223..b3e9103 100644
--- a/app/Domains/Cart/Models/Cart.php
+++ b/app/Domains/Cart/Models/Cart.php
@@ -115,8 +115,9 @@ class Cart extends Model
             $delta = $quantity - $item->cantidad;
 
             if ($delta > 0 && $variant->stock_tecnico < $delta) {
+                $maxAvailable = $variant->stock_tecnico + $item->cantidad;
                 throw ValidationException::withMessages([
-                    'cantidad' => "El máximo que se puede agregar es {$variant->stock_tecnico}.",
+                    'cantidad' => "El máximo que se puede agregar es {$maxAvailable}.",
                 ]);
             }
 
diff --git a/tests/Feature/Cart/CartControllerTest.php b/tests/Feature/Cart/CartControllerTest.php
index 61a008e..fc10d69 100644
--- a/tests/Feature/Cart/CartControllerTest.php
+++ b/tests/Feature/Cart/CartControllerTest.php
@@ -312,7 +312,7 @@ class CartControllerTest extends TestCase
 
         $response2
             ->assertUnprocessable()
-            ->assertJsonValidationErrors(['cantidad']);
+            ->assertJsonValidationErrors(['cantidad' => 'El máximo que se puede agregar es 2.']);
     }
 
     protected function createVariantForTenant(