diff --git a/appengine/standard/endpoints-frameworks-v2/echo/main.py b/appengine/standard/endpoints-frameworks-v2/echo/main.py
index 1922dead254..ce1a144976b 100644
--- a/appengine/standard/endpoints-frameworks-v2/echo/main.py
+++ b/appengine/standard/endpoints-frameworks-v2/echo/main.py
@@ -92,7 +92,8 @@ def echo_api_key(self, request):
         # Require auth tokens to have the following scopes to access this API.
         scopes=[endpoints.EMAIL_SCOPE],
         # OAuth2 audiences allowed in incoming tokens.
-        audiences=['your-oauth-client-id.com'])
+        audiences=['your-oauth-client-id.com'],
+        allowed_client_ids=['your-oauth-client-id.com'])
     def get_user_email(self, request):
         user = endpoints.get_current_user()
         # If there's no user defined, the request was unauthenticated, so we