diff --git a/cmd/hichipbridge/config.sample.json b/cmd/hichipbridge/config.sample.json
index a0ad7d7..90582f3 100644
--- a/cmd/hichipbridge/config.sample.json
+++ b/cmd/hichipbridge/config.sample.json
@@ -2,6 +2,7 @@
     "log_file": "stderr",
     "log_level": "debug",
     "backend_config": {
+        "save_workers_size": 1,
         "log_received_mails": false
     },
     "servers": [{