diff --git a/app/Client/Client.php b/app/Client/Client.php
index 1df84b7..178201e 100644
--- a/app/Client/Client.php
+++ b/app/Client/Client.php
@@ -65,13 +65,13 @@ class Client
                 });
 
                 $connection->on('authenticationFailed', function ($data) use ($deferred) {
-                    $this->logger->error("Authentication failed. Please check your authentication token and try again.");
+                    $this->logger->error($data->data->message);
 
                     $this->exit($deferred);
                 });
 
                 $connection->on('subdomainTaken', function ($data) use ($deferred) {
-                    $this->logger->error("The chosen subdomain \"{$data->data->subdomain}\" is already taken. Please choose a different subdomain.");
+                    $this->logger->error($data->data->message);
 
                     $this->exit($deferred);
                 });
diff --git a/app/Server/Http/Controllers/ControlMessageController.php b/app/Server/Http/Controllers/ControlMessageController.php
index a088c4e..97eed7e 100644
--- a/app/Server/Http/Controllers/ControlMessageController.php
+++ b/app/Server/Http/Controllers/ControlMessageController.php
@@ -95,7 +95,9 @@ class ControlMessageController implements MessageComponentInterface
             }, function () use ($connection) {
                 $connection->send(json_encode([
                     'event' => 'authenticationFailed',
-                    'data' => []
+                    'data' => [
+                        'message' => config('expose.admin.messages.invalid_auth_token')
+                    ]
                 ]));
                 $connection->close();
             });
@@ -148,10 +150,13 @@ class ControlMessageController implements MessageComponentInterface
         if (!is_null($subdomain)) {
             $controlConnection = $this->connectionManager->findControlConnectionForSubdomain($subdomain);
             if (!is_null($controlConnection) || $subdomain === config('expose.admin.subdomain')) {
+                $message = config('expose.admin.messages.subdomain_taken');
+                $message = str_replace(':subdomain', $subdomain, $message);
+
                 $connection->send(json_encode([
                     'event' => 'subdomainTaken',
                     'data' => [
-                        'subdomain' => $subdomain,
+                        'message' => $message,
                     ]
                 ]));
                 $connection->close();
diff --git a/config/expose.php b/config/expose.php
index bc7c57a..e5ccaa4 100644
--- a/config/expose.php
+++ b/config/expose.php
@@ -9,8 +9,7 @@ return [
 
         'database' => base_path('database/expose.db'),
 
-        'validate_auth_tokens' => false,
-
+        'validate_auth_tokens' => true,
 
         /*
         |--------------------------------------------------------------------------
@@ -74,5 +73,11 @@ return [
         |
         */
         'user_repository' => \App\Server\UserRepository\DatabaseUserRepository::class,
+
+        'messages' => [
+            'invalid_auth_token' => 'Authentication failed. Please check your authentication token and try again.',
+
+            'subdomain_taken' => 'The chosen subdomain :subdomain is already taken. Please choose a different subdomain.',
+        ]
     ]
 ];