diff --git a/app/src/main/java/io/nekohasekai/sfa/bg/BoxService.kt b/app/src/main/java/io/nekohasekai/sfa/bg/BoxService.kt
index c78172a..e753d06 100644
--- a/app/src/main/java/io/nekohasekai/sfa/bg/BoxService.kt
+++ b/app/src/main/java/io/nekohasekai/sfa/bg/BoxService.kt
@@ -17,7 +17,6 @@ import io.nekohasekai.libbox.BoxService
 import io.nekohasekai.libbox.CommandServer
 import io.nekohasekai.libbox.CommandServerHandler
 import io.nekohasekai.libbox.Libbox
-import io.nekohasekai.libbox.PProfServer
 import io.nekohasekai.libbox.PlatformInterface
 import io.nekohasekai.libbox.SystemProxyStatus
 import io.nekohasekai.sfa.Application
@@ -89,7 +88,6 @@ class BoxService(
     private val notification = ServiceNotification(status, service)
     private var boxService: BoxService? = null
     private var commandServer: CommandServer? = null
-    private var pprofServer: PProfServer? = null
     private var receiverRegistered = false
     private val receiver = object : BroadcastReceiver() {
         override fun onReceive(context: Context, intent: Intent) {
diff --git a/app/src/main/java/io/nekohasekai/sfa/bg/ServiceNotification.kt b/app/src/main/java/io/nekohasekai/sfa/bg/ServiceNotification.kt
index 0d58383..271e652 100644
--- a/app/src/main/java/io/nekohasekai/sfa/bg/ServiceNotification.kt
+++ b/app/src/main/java/io/nekohasekai/sfa/bg/ServiceNotification.kt
@@ -44,6 +44,7 @@ class ServiceNotification(
 
     private val commandClient =
         CommandClient(GlobalScope, CommandClient.ConnectionType.Status, this)
+    private var receiverRegistered = false
 
     private val notificationBuilder by lazy {
         NotificationCompat.Builder(service, notificationChannel).setShowWhen(false).setOngoing(true)
@@ -103,6 +104,7 @@ class ServiceNotification(
             addAction(Intent.ACTION_SCREEN_ON)
             addAction(Intent.ACTION_SCREEN_OFF)
         })
+        receiverRegistered = true
     }
 
     override fun updateStatus(status: StatusMessage) {
@@ -129,6 +131,9 @@ class ServiceNotification(
     fun close() {
         commandClient.disconnect()
         ServiceCompat.stopForeground(service, ServiceCompat.STOP_FOREGROUND_REMOVE)
-        service.unregisterReceiver(this)
+        if (receiverRegistered) {
+            service.unregisterReceiver(this)
+            receiverRegistered = false
+        }
     }
 }
\ No newline at end of file