diff --git a/mobile/src/main/scala/com/github/shadowsocks/BaseService.scala b/mobile/src/main/scala/com/github/shadowsocks/BaseService.scala
index 30e4b977..3c9835e1 100644
--- a/mobile/src/main/scala/com/github/shadowsocks/BaseService.scala
+++ b/mobile/src/main/scala/com/github/shadowsocks/BaseService.scala
@@ -21,16 +21,14 @@
 package com.github.shadowsocks
 
 import java.io.{File, IOException}
+import java.net.{Inet6Address, InetAddress}
 import java.util
 import java.util.concurrent.TimeUnit
 import java.util.{Timer, TimerTask}
-import java.net.InetAddress
-import java.net.Inet6Address
 
 import android.app.Service
 import android.content.{BroadcastReceiver, Context, Intent, IntentFilter}
-import android.os.{Handler, IBinder, RemoteCallbackList}
-import android.support.v4.os.BuildCompat
+import android.os.{Build, Handler, IBinder, RemoteCallbackList}
 import android.text.TextUtils
 import android.util.Log
 import android.widget.Toast
@@ -166,7 +164,7 @@ trait BaseService extends Service {
   def startRunner(profile: Profile) {
     this.profile = profile
 
-    if (BuildCompat.isAtLeastO) startForegroundService(new Intent(this, getClass))
+    if (Build.VERSION.SDK_INT >= 26) startForegroundService(new Intent(this, getClass))
     else startService(new Intent(this, getClass))
     TrafficMonitor.reset()
     trafficMonitorThread = new TrafficMonitorThread(getApplicationContext)
diff --git a/mobile/src/main/scala/com/github/shadowsocks/ShadowsocksApplication.scala b/mobile/src/main/scala/com/github/shadowsocks/ShadowsocksApplication.scala
index 72f8b006..9ad88c31 100644
--- a/mobile/src/main/scala/com/github/shadowsocks/ShadowsocksApplication.scala
+++ b/mobile/src/main/scala/com/github/shadowsocks/ShadowsocksApplication.scala
@@ -29,7 +29,6 @@ import android.content._
 import android.content.res.Configuration
 import android.os.{Build, LocaleList}
 import android.preference.PreferenceManager
-import android.support.v4.os.BuildCompat
 import android.support.v7.app.AppCompatDelegate
 import android.util.Log
 import com.evernote.android.job.JobManager
@@ -43,8 +42,8 @@ import com.google.firebase.remoteconfig.FirebaseRemoteConfig
 import com.j256.ormlite.logger.LocalLog
 import eu.chainfire.libsuperuser.Shell
 
-import scala.collection.mutable.ArrayBuffer
 import scala.collection.JavaConversions._
+import scala.collection.mutable.ArrayBuffer
 
 object ShadowsocksApplication {
   var app: ShadowsocksApplication = _
@@ -157,7 +156,7 @@ class ShadowsocksApplication extends Application {
 
     TcpFastOpen.enabled(settings.getBoolean(Key.tfo, TcpFastOpen.sendEnabled))
 
-    if (BuildCompat.isAtLeastO) getSystemService(classOf[NotificationManager]).createNotificationChannels(List(
+    if (Build.VERSION.SDK_INT >= 26) getSystemService(classOf[NotificationManager]).createNotificationChannels(List(
       new NotificationChannel("service-vpn", getText(R.string.service_vpn), NotificationManager.IMPORTANCE_MIN),
       new NotificationChannel("service-nat", getText(R.string.service_nat), NotificationManager.IMPORTANCE_LOW)
     ))
diff --git a/mobile/src/main/scala/com/github/shadowsocks/ShadowsocksRunnerService.scala b/mobile/src/main/scala/com/github/shadowsocks/ShadowsocksRunnerService.scala
index 75f7d832..6c089d02 100644
--- a/mobile/src/main/scala/com/github/shadowsocks/ShadowsocksRunnerService.scala
+++ b/mobile/src/main/scala/com/github/shadowsocks/ShadowsocksRunnerService.scala
@@ -23,7 +23,7 @@ package com.github.shadowsocks
 import android.app.Service
 import android.content.Intent
 import android.net.VpnService
-import android.os.{Handler, IBinder}
+import android.os.{Build, Handler, IBinder}
 import android.support.v4.app.NotificationCompat
 import android.support.v4.os.BuildCompat
 import com.github.shadowsocks.ShadowsocksApplication.app
@@ -49,7 +49,7 @@ class ShadowsocksRunnerService extends Service with ServiceBoundContext {
 
   override def onCreate() {
     super.onCreate()
-    if (BuildCompat.isAtLeastO) {
+    if (Build.VERSION.SDK_INT >= 26) {
       val builder = new NotificationCompat.Builder(this)
       builder.setPriority(NotificationCompat.PRIORITY_MIN)
       startForeground(1, builder.build)
diff --git a/mobile/src/main/scala/com/github/shadowsocks/utils/Utils.scala b/mobile/src/main/scala/com/github/shadowsocks/utils/Utils.scala
index 29c54340..5bda5098 100644
--- a/mobile/src/main/scala/com/github/shadowsocks/utils/Utils.scala
+++ b/mobile/src/main/scala/com/github/shadowsocks/utils/Utils.scala
@@ -28,7 +28,6 @@ import android.content.pm.PackageManager
 import android.content.{Context, Intent}
 import android.graphics._
 import android.os.Build
-import android.support.v4.os.BuildCompat
 import android.util.{Base64, DisplayMetrics, Log}
 import android.view.View.MeasureSpec
 import android.view.{Gravity, View, Window}
@@ -139,7 +138,7 @@ object Utils {
 
   def startSsService(context: Context) {
     val intent = new Intent(context, classOf[ShadowsocksRunnerService])
-    if (BuildCompat.isAtLeastO) context.startForegroundService(intent)
+    if (Build.VERSION.SDK_INT >= 26) context.startForegroundService(intent)
     else context.startService(intent)
   }