diff --git a/conf/frps.ini b/conf/frps.ini
index e1e90418..4a6d47f8 100644
--- a/conf/frps.ini
+++ b/conf/frps.ini
@@ -19,6 +19,7 @@ log_max_days = 3
 # if you enable privilege mode, frpc can create a proxy without pre-configure in frps when privilege_token is correct
 privilege_mode = true
 privilege_token = 12345678
+# only allow frpc to bind ports you list, if you set nothing, there won't be any limit
 privilege_allow_ports = 2000-3000,3001,3003,4000-50000
 # pool_count in each proxy will change to max_pool_count if they exceed the maximum value
 max_pool_count = 100
diff --git a/src/cmd/frps/control.go b/src/cmd/frps/control.go
index 7214d482..4c9910aa 100644
--- a/src/cmd/frps/control.go
+++ b/src/cmd/frps/control.go
@@ -251,11 +251,13 @@ func doLogin(req *msg.ControlReq, c *conn.Conn) (ret int64, info string) {
 			// we check listen_port if privilege_allow_ports are set
 			// and PrivilegeMode is enabled
 			if s.Type == "tcp" {
-				_, ok := server.PrivilegeAllowPorts[s.ListenPort]
-				if !ok {
-					info = fmt.Sprintf("ProxyName [%s], remote_port [%d] isn't allowed", req.ProxyName, s.ListenPort)
-					log.Warn(info)
-					return
+				if len(server.PrivilegeAllowPorts) != 0 {
+					_, ok := server.PrivilegeAllowPorts[s.ListenPort]
+					if !ok {
+						info = fmt.Sprintf("ProxyName [%s], remote_port [%d] isn't allowed", req.ProxyName, s.ListenPort)
+						log.Warn(info)
+						return
+					}
 				}
 			}
 			err := server.CreateProxy(s)