diff --git a/README.md b/README.md
index 4baf088..75a29ef 100644
--- a/README.md
+++ b/README.md
@@ -214,7 +214,7 @@ exports.security = {
     headerName: 'x-csrf-token', // request csrf token's name in header
     bodyName: '_csrf',          // request csrf token's name in body
     queryName: '_csrf',         // request csrf token's name in query
-    rotateWhenInvalid: false,   // rotate csrf secret when csrf token invalid
+    rotateWhenInvalid: false,   // rotate csrf secret when csrf token invalid. For multi applications which be deployed on the same domain, as tokens from one application may impact others.
     refererWhiteList: [],       // referer white list
     supportedRequests: [        // supported URL path and method, the package will match URL path regex patterns one by one until path matched. We recommend you set {path: /^\//, methods:['POST','PATCH','DELETE','PUT','CONNECT']} as the last rule in the list, which is also the default config.
       {path: /^\//, methods:['POST','PATCH','DELETE','PUT','CONNECT']}
diff --git a/README.zh-CN.md b/README.zh-CN.md
index 0ff04dd..7288f5e 100644
--- a/README.zh-CN.md
+++ b/README.zh-CN.md
@@ -143,7 +143,7 @@ exports.security = {
     headerName: 'x-csrf-token', // csrf token 在 header 中的名称
     bodyName: '_csrf',          // csrf token 在 body 中的名称
     queryName: '_csrf',         // csrf token 在 query 中的名称
-    rotateWhenInvalid: false,   // csrf invalid 时刷新 token
+    rotateWhenInvalid: false,   // csrf invalid 时刷新 token，用于同域名下多个业务 token 可能互相影响的情况
     refererWhiteList: [],       // referer 白名单
     supportedRequests: [        // 支持的 url path pattern 和方法，根据配置名单由上至下匹配 url path 正则，建议在自定义时配置 {path: /^\//, methods:['POST','PATCH','DELETE','PUT','CONNECT']} 为兜底规则
       {path: /^\//, methods:['POST','PATCH','DELETE','PUT','CONNECT']},