diff --git a/src/main/res/values-zh-rCN/strings.xml b/src/main/res/values-zh-rCN/strings.xml
index 2841fe5d..e26c12ec 100644
--- a/src/main/res/values-zh-rCN/strings.xml
+++ b/src/main/res/values-zh-rCN/strings.xml
@@ -32,6 +32,7 @@
   <string name="auto_connect_summary">随系统启动后台服务</string>
   <string name="forward_success">后台服务已开始运行。</string>
   <string name="service_failed">无法连接远程服务器</string>
+  <string name="invalid_server">服务器名无效</string>
   <string name="nat_deprecated">警告：在 Android 5.0 及更高版本中不建议使用 NAT 模式</string>
   <string name="nat_no_root">NAT 模式需要 ROOT 权限</string>
   <string name="switch_to_vpn">切换到 VPN 模式</string>
diff --git a/src/main/res/values-zh-rTW/strings.xml b/src/main/res/values-zh-rTW/strings.xml
index 233cb03a..1e834384 100644
--- a/src/main/res/values-zh-rTW/strings.xml
+++ b/src/main/res/values-zh-rTW/strings.xml
@@ -33,6 +33,7 @@
   <string name="auto_connect_summary">在裝置啟動時啟用 Shadowsocks</string>
   <string name="forward_success">Shadowsocks 已啟動。</string>
   <string name="service_failed">連線至遠端伺服器失敗</string>
+  <string name="invalid_server">伺服器名无效</string>
   <string name="nat_deprecated">警告：自 Android 5.0 開始， NAT 模式已過時</string>
   <string name="nat_no_root">NAT 模式需要 ROOT 權限</string>
   <string name="switch_to_vpn">切換至 VPN 模式</string>
diff --git a/src/main/res/values/strings.xml b/src/main/res/values/strings.xml
index c29c3c87..bac91e4c 100644
--- a/src/main/res/values/strings.xml
+++ b/src/main/res/values/strings.xml
@@ -64,6 +64,7 @@
 
   <!-- notification category -->
   <string name="forward_success">Shadowsocks started.</string>
+  <string name="invalid_server">Invalid server name</string>
   <string name="service_failed">Failed to connect the remote server</string>
   <string name="nat_deprecated">WARNING: NAT mode has been deprecated since Android 5.0</string>
   <string name="nat_no_root">NAT mode requires ROOT permission</string>
diff --git a/src/main/scala/com/github/shadowsocks/ShadowsocksNatService.scala b/src/main/scala/com/github/shadowsocks/ShadowsocksNatService.scala
index 46fc72f9..83cbe023 100644
--- a/src/main/scala/com/github/shadowsocks/ShadowsocksNatService.scala
+++ b/src/main/scala/com/github/shadowsocks/ShadowsocksNatService.scala
@@ -418,11 +418,12 @@ class ShadowsocksNatService extends BaseService {
           resolved = true
         }
 
-        if (resolved && handleConnection) {
-
+        if (!resolved) {
+          changeState(State.STOPPED, getString(R.string.invalid_server))
+          stopRunner(true)
+        } else if (handleConnection) {
           // Set DNS
           flushDns()
-
           changeState(State.CONNECTED)
           notification = new ShadowsocksNotification(this, config.profileName, true)
         } else {
diff --git a/src/main/scala/com/github/shadowsocks/ShadowsocksVpnService.scala b/src/main/scala/com/github/shadowsocks/ShadowsocksVpnService.scala
index 96040774..91d18537 100644
--- a/src/main/scala/com/github/shadowsocks/ShadowsocksVpnService.scala
+++ b/src/main/scala/com/github/shadowsocks/ShadowsocksVpnService.scala
@@ -216,7 +216,10 @@ class ShadowsocksVpnService extends VpnService with BaseService {
           resolved = true
         }
 
-        if (resolved && handleConnection) {
+        if (!resolved) {
+          changeState(State.STOPPED, getString(R.string.invalid_server))
+          stopRunner(true)
+        } else if (handleConnection) {
           changeState(State.CONNECTED)
           notification = new ShadowsocksNotification(this, config.profileName)
         } else {