diff --git a/README.md b/README.md
index baac3dc..79b8cb0 100644
--- a/README.md
+++ b/README.md
@@ -70,6 +70,7 @@ See the [YAML config example](config/config.yml):
 ```yaml
 core:
   enabled: true # enabale httpd server
+  address: "" # ip address to bind (default: any)
   port: "8088" # ignore this port number if auto_tls is enabled (listen 443).
   worker_num: 0 # default worker number is runtime.NumCPU()
   queue_num: 0 # default queue number is 8192
diff --git a/config/config.yml b/config/config.yml
index 44a9c93..cdc5a4d 100644
--- a/config/config.yml
+++ b/config/config.yml
@@ -1,5 +1,6 @@
 core:
   enabled: true # enabale httpd server
+  address: "" # ip address to bind (default: any)
   port: "8088" # ignore this port number if auto_tls is enabled (listen 443).
   worker_num: 0 # default worker number is runtime.NumCPU()
   queue_num: 0 # default queue number is 8192