diff --git a/flytekit/clients/grpc_utils/auth_interceptor.py b/flytekit/clients/grpc_utils/auth_interceptor.py
index 21bcc301368..a358a0d9237 100644
--- a/flytekit/clients/grpc_utils/auth_interceptor.py
+++ b/flytekit/clients/grpc_utils/auth_interceptor.py
@@ -32,10 +32,9 @@ def _call_details_with_auth_metadata(self, client_call_details: grpc.ClientCallD
         """
         Returns new ClientCallDetails with metadata added.
         """
-        metadata = None
+        metadata = [("accept", "application/grpc")]
         auth_metadata = self._authenticator.fetch_grpc_call_auth_metadata()
         if auth_metadata:
-            metadata = []
             if client_call_details.metadata:
                 metadata.extend(list(client_call_details.metadata))
             metadata.append(auth_metadata)