diff --git a/package/ntlf9t/luci-app-smartdns/Makefile b/package/ntlf9t/luci-app-smartdns/Makefile
index 3693dc6c86..f756aed990 100644
--- a/package/ntlf9t/luci-app-smartdns/Makefile
+++ b/package/ntlf9t/luci-app-smartdns/Makefile
@@ -7,7 +7,7 @@ LUCI_DEPENDS:=+smartdns
 LUCI_PKGARCH:=all
 PKG_NAME:=luci-app-smartdns
 PKG_VERSION:=1
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 include $(TOPDIR)/feeds/luci/luci.mk
 
diff --git a/package/ntlf9t/luci-app-smartdns/luasrc/model/cbi/smartdns/smartdns.lua b/package/ntlf9t/luci-app-smartdns/luasrc/model/cbi/smartdns/smartdns.lua
index c823dfdd2c..6a3414d9cc 100644
--- a/package/ntlf9t/luci-app-smartdns/luasrc/model/cbi/smartdns/smartdns.lua
+++ b/package/ntlf9t/luci-app-smartdns/luasrc/model/cbi/smartdns/smartdns.lua
@@ -83,6 +83,14 @@ o.cfgvalue    = function(...)
     return Flag.cfgvalue(...) or "0"
 end
 
+---- Serve expired
+o = s:taboption("settings", Flag, "serve_expired", translate("Serve expired"), translate("Attempts to serve old responses from cache with a TTL of 0 in the response without waiting for the actual resolution to finish."))
+o.rmempty     = false
+o.default     = o.disabled
+o.cfgvalue    = function(...)
+    return Flag.cfgvalue(...) or "0"
+end
+
 ---- Redirect
 o = s:taboption("settings", ListValue, "redirect", translate("Redirect"), translate("SmartDNS redirect mode"))
 o.placeholder = "none"
@@ -240,7 +248,8 @@ s:option(Value, "name", translate("DNS Server Name"), translate("DNS Server Name
 ---- IP address
 o = s:option(Value, "ip", translate("ip"), translate("DNS Server ip"))
 o.datatype = "or(ipaddr, string)"
-o.rmempty = false 
+o.rmempty = false
+
 ---- port
 o = s:option(Value, "port", translate("port"), translate("DNS Server port"))
 o.placeholder = "default"
@@ -326,4 +335,3 @@ o.write = function()
 end
 
 return m
-
diff --git a/package/ntlf9t/luci-app-smartdns/po/zh_Hans/smartdns.po b/package/ntlf9t/luci-app-smartdns/po/zh_Hans/smartdns.po
index 0d9579b1de..a712f0d2eb 100644
--- a/package/ntlf9t/luci-app-smartdns/po/zh_Hans/smartdns.po
+++ b/package/ntlf9t/luci-app-smartdns/po/zh_Hans/smartdns.po
@@ -73,6 +73,12 @@ msgstr "域名预加载"
 msgid "Enable domain prefetch, accelerate domain response speed."
 msgstr "启用域名预加载，加速域名响应速度。"
 
+msgid "Serve expired"
+msgstr "缓存过期服务"
+
+msgid "Attempts to serve old responses from cache with a TTL of 0 in the response without waiting for the actual resolution to finish."
+msgstr "查询性能优化，有请求时尝试回应TTL为0的过期记录，以避免查询等待。"
+
 msgid "Redirect"
 msgstr "重定向"
 
diff --git a/package/ntlf9t/smartdns/Makefile b/package/ntlf9t/smartdns/Makefile
index f300d947dd..feda1c7b79 100644
--- a/package/ntlf9t/smartdns/Makefile
+++ b/package/ntlf9t/smartdns/Makefile
@@ -17,7 +17,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=smartdns
 PKG_VERSION:=2.2020.19
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_SOURCE_PROTO:=git
 PKG_SOURCE_URL:=https://github.com/pymumu/smartdns.git
diff --git a/package/ntlf9t/smartdns/conf/smartdns.conf b/package/ntlf9t/smartdns/conf/smartdns.conf
index f082049455..3af0356942 100644
--- a/package/ntlf9t/smartdns/conf/smartdns.conf
+++ b/package/ntlf9t/smartdns/conf/smartdns.conf
@@ -2,6 +2,7 @@ config smartdns
 	option server_name 'smartdns'
 	option dualstack_ip_selection '1'
 	option prefetch_domain '1'
+	option serve_expired '1'
 	option seconddns_no_speed_check '0'
 	option seconddns_no_dualstack_selection '0'
 	option seconddns_no_cache '0'