Use the correct proto for benchmark_serivce
diff --git a/src/python/grpcio_tests/tests/qps/worker_server.py b/src/python/grpcio_tests/tests/qps/worker_server.py
index db145fb..740bdcf 100644
--- a/src/python/grpcio_tests/tests/qps/worker_server.py
+++ b/src/python/grpcio_tests/tests/qps/worker_server.py
@@ -20,6 +20,7 @@
 from concurrent import futures
 import grpc
 from src.proto.grpc.testing import control_pb2
+from src.proto.grpc.testing import benchmark_service_pb2_grpc
 from src.proto.grpc.testing import worker_service_pb2_grpc
 from src.proto.grpc.testing import stats_pb2
 
@@ -72,7 +73,7 @@
         server = test_common.test_server(max_workers=server_threads)
         if config.server_type == control_pb2.ASYNC_SERVER:
             servicer = benchmark_server.BenchmarkServer()
-            worker_service_pb2_grpc.add_BenchmarkServiceServicer_to_server(
+            benchmark_service_pb2_grpc.add_BenchmarkServiceServicer_to_server(
                 servicer, server)
         elif config.server_type == control_pb2.ASYNC_GENERIC_SERVER:
             resp_size = config.payload_config.bytebuf_params.resp_size