diff --git a/src/python/grpcio_tests/tests_py3_only/interop/xds_interop_client.py b/src/python/grpcio_tests/tests_py3_only/interop/xds_interop_client.py
index 2258989208897..0d3d03337362b 100644
--- a/src/python/grpcio_tests/tests_py3_only/interop/xds_interop_client.py
+++ b/src/python/grpcio_tests/tests_py3_only/interop/xds_interop_client.py
@@ -14,7 +14,7 @@
 
 import argparse
 import collections
-import concurrent
+import concurrent.futures
 import datetime
 import logging
 import signal
@@ -108,7 +108,8 @@ def __init__(self, start: int, end: int, metadata_keys: Iterable[str]):
             messages_pb2.LoadBalancerStatsResponse.MetadataByPeer
         )
 
-    def _sanitize_metadata_key(self, metadata_key: str) -> str:
+    @classmethod
+    def _sanitize_metadata_key(cls, metadata_key: str) -> str:
         return metadata_key.strip().lower()
 
     def _add_metadata(