diff --git a/tests/unittests/auth/test_auth_handler.py b/tests/unittests/auth/test_auth_handler.py
index 20a3f8e4..2a65f779 100644
--- a/tests/unittests/auth/test_auth_handler.py
+++ b/tests/unittests/auth/test_auth_handler.py
@@ -456,7 +456,10 @@ class TestExchangeAuthToken:
       self, auth_config_with_auth_code, monkeypatch
   ):
     """Test when token exchange is not supported."""
-    monkeypatch.setattr("google.adk.auth.auth_handler.AUTHLIB_AVAILABLE", False)
+    monkeypatch.setattr(
+        "google.adk.auth.exchanger.oauth2_credential_exchanger.AUTHLIB_AVAILABLE",
+        False,
+    )
 
     handler = AuthHandler(auth_config_with_auth_code)
     result = await handler.exchange_auth_token()