diff --git a/Checkout.php b/Checkout.php
index cd0ea8d..3108298 100644
--- a/Checkout.php
+++ b/Checkout.php
@@ -194,6 +194,9 @@ class Checkout extends Component
                     $validationRules = array_merge($validationRules, explode('|', $config['validation']));
                 }
             }
+            if ($config['name'] === 'hostname') {
+                $validationRules = ['required', 'string', 'regex:/^[a-zA-Z0-9]+\.[a-zA-Z0-9]+(\.[a-zA-Z0-9]+)*$/'];
+            }
             if (count($validationRules) > 0) {
                 $rules["checkoutConfig.{$config['name']}"] = $validationRules;
             }