diff --git a/tests/client/test_auth.py b/tests/client/test_auth.py
index 6f91ba10f4..9c306a6be1 100644
--- a/tests/client/test_auth.py
+++ b/tests/client/test_auth.py
@@ -11,7 +11,7 @@
 
 import httpx
 import pytest
-from pydantic import AnyHttpUrl
+from pydantic import AnyHttpUrl, AnyUrl
 
 from mcp.client.auth import (
     ClientCredentialsProvider,
@@ -91,6 +91,7 @@ def oauth_metadata():
             "authorization_code",
             "refresh_token",
             "client_credentials",
+            "token-exchange",
         ],
         code_challenge_methods_supported=["S256"],
     )
@@ -1014,6 +1015,7 @@ def test_build_metadata(
             "authorization_code",
             "refresh_token",
             "client_credentials",
+            "token-exchange",
         ],
         token_endpoint_auth_methods_supported=["client_secret_post"],
         service_documentation=AnyHttpUrl(service_documentation_url),
diff --git a/tests/server/fastmcp/auth/test_auth_integration.py b/tests/server/fastmcp/auth/test_auth_integration.py
index 3063eaa347..a267ed4360 100644
--- a/tests/server/fastmcp/auth/test_auth_integration.py
+++ b/tests/server/fastmcp/auth/test_auth_integration.py
@@ -417,6 +417,7 @@ async def test_metadata_endpoint(self, test_client: httpx.AsyncClient):
             "authorization_code",
             "refresh_token",
             "client_credentials",
+            "token-exchange",
         ]
         assert metadata["service_documentation"] == "https://docs.example.com/"
 
@@ -1030,7 +1031,7 @@ async def test_client_registration_invalid_grant_type(
         assert error_data["error"] == "invalid_client_metadata"
         assert error_data["error_description"] == (
             "grant_types must be authorization_code and "
-            "refresh_token or client_credentials"
+            "refresh_token or client_credentials or token exchange"
         )
 
     @pytest.mark.anyio
@@ -1361,10 +1362,7 @@ async def test_metadata_includes_token_exchange(
         response = await test_client.get("/.well-known/oauth-authorization-server")
         assert response.status_code == 200
         metadata = response.json()
-        assert (
-            "token-exchange"
-            in metadata["grant_types_supported"]
-        )
+        assert "token-exchange" in metadata["grant_types_supported"]
 
     @pytest.mark.anyio
     @pytest.mark.parametrize(