diff --git a/src/Server/Http/Controllers/OAuthRegisterController.php b/src/Server/Http/Controllers/OAuthRegisterController.php
index f8edcb3e..66097e5c 100644
--- a/src/Server/Http/Controllers/OAuthRegisterController.php
+++ b/src/Server/Http/Controllers/OAuthRegisterController.php
@@ -46,9 +46,9 @@ public function __invoke(Request $request): JsonResponse
 
         return response()->json([
             'client_id' => (string) $client->id,
-            'grant_types' => $client->grantTypes,
+            'grant_types' => $client->grant_types,
             'response_types' => ['code'],
-            'redirect_uris' => $client->redirectUris,
+            'redirect_uris' => $client->redirect_uris,
             'scope' => 'mcp:use',
             'token_endpoint_auth_method' => 'none',
         ]);
diff --git a/tests/Unit/Server/RegistrarTest.php b/tests/Unit/Server/RegistrarTest.php
index ad9aaf33..fcb34744 100644
--- a/tests/Unit/Server/RegistrarTest.php
+++ b/tests/Unit/Server/RegistrarTest.php
@@ -169,8 +169,8 @@ class ClientRepository {
                 public function createAuthorizationCodeGrantClient(string $name, array $redirectUris, bool $confidential = true, $user = null, bool $enableDeviceFlow = false) {
                     return (object) [
                         "id" => "test-client-id",
-                        "grantTypes" => ["authorization_code"],
-                        "redirectUris" => $redirectUris,
+                        "grant_types" => ["authorization_code"],
+                        "redirect_uris" => $redirectUris,
                     ];
                 }
             }
@@ -207,8 +207,8 @@ class ClientRepository {
                 public function createAuthorizationCodeGrantClient(string $name, array $redirectUris, bool $confidential = true, $user = null, bool $enableDeviceFlow = false) {
                     return (object) [
                         "id" => "test-client-id",
-                        "grantTypes" => ["authorization_code"],
-                        "redirectUris" => $redirectUris,
+                        "grant_types" => ["authorization_code"],
+                        "redirect_uris" => $redirectUris,
                     ];
                 }
             }
@@ -247,8 +247,8 @@ class ClientRepository {
                 public function createAuthorizationCodeGrantClient(string $name, array $redirectUris, bool $confidential = true, $user = null, bool $enableDeviceFlow = false) {
                     return (object) [
                         "id" => "test-client-id",
-                        "grantTypes" => ["authorization_code"],
-                        "redirectUris" => $redirectUris,
+                        "grant_types" => ["authorization_code"],
+                        "redirect_uris" => $redirectUris,
                     ];
                 }
             }