diff --git a/src/google/adk/auth/exchanger/oauth2_credential_exchanger.py b/src/google/adk/auth/exchanger/oauth2_credential_exchanger.py
index 4231a7c1ed..e4ccb5e006 100644
--- a/src/google/adk/auth/exchanger/oauth2_credential_exchanger.py
+++ b/src/google/adk/auth/exchanger/oauth2_credential_exchanger.py
@@ -92,6 +92,7 @@ async def exchange(
           authorization_response=auth_credential.oauth2.auth_response_uri,
           code=auth_credential.oauth2.auth_code,
           grant_type=OAuthGrantType.AUTHORIZATION_CODE,
+          client_id=auth_credential.oauth2.client_id,
       )
       update_credential_with_tokens(auth_credential, tokens)
       logger.debug("Successfully exchanged OAuth2 tokens")