diff --git a/src/main/AndroidManifest.xml b/src/main/AndroidManifest.xml
index ea9f5bbe..95c4bbf7 100644
--- a/src/main/AndroidManifest.xml
+++ b/src/main/AndroidManifest.xml
@@ -68,8 +68,7 @@
                 android:name=".ProfileConfigActivity"
                 android:excludeFromRecents="true"
                 android:label="Profile config"
-                android:launchMode="singleTask"
-                android:parentActivityName=".MainActivity"/>
+                android:launchMode="singleTask"/>
 
         <activity
                 android:name=".ShadowsocksRunnerActivity"
diff --git a/src/main/scala/com/github/shadowsocks/ProfileConfigActivity.scala b/src/main/scala/com/github/shadowsocks/ProfileConfigActivity.scala
index 34d2264b..b3e56128 100644
--- a/src/main/scala/com/github/shadowsocks/ProfileConfigActivity.scala
+++ b/src/main/scala/com/github/shadowsocks/ProfileConfigActivity.scala
@@ -1,9 +1,13 @@
 package com.github.shadowsocks
 
 import android.app.Activity
+import android.content.DialogInterface
 import android.os.Bundle
+import android.support.v7.app.AlertDialog
 import android.support.v7.widget.Toolbar
 import android.support.v7.widget.Toolbar.OnMenuItemClickListener
+import com.github.shadowsocks.ShadowsocksApplication.app
+import com.github.shadowsocks.utils.Key
 
 class ProfileConfigActivity extends Activity {
   override def onCreate(savedInstanceState: Bundle) {
@@ -12,9 +16,16 @@ class ProfileConfigActivity extends Activity {
     val toolbar = findViewById(R.id.toolbar).asInstanceOf[Toolbar]
     toolbar.setTitle("Profile config")  // TODO
     toolbar.setNavigationIcon(R.drawable.ic_navigation_close)
-    toolbar.setNavigationOnClickListener(_ => finish())
+    toolbar.setNavigationOnClickListener(_ => onBackPressed())
     toolbar.inflateMenu(R.menu.profile_config_menu)
     toolbar.setOnMenuItemClickListener(getFragmentManager.findFragmentById(R.id.content)
       .asInstanceOf[OnMenuItemClickListener])
   }
+
+  override def onBackPressed(): Unit = if (app.settings.getBoolean(Key.dirty, false)) new AlertDialog.Builder(this)
+    .setTitle("Confirm?") // TODO
+    .setPositiveButton(android.R.string.yes, ((_, _) => finish()): DialogInterface.OnClickListener)
+    .setNegativeButton(android.R.string.no, null)
+    .create()
+    .show() else super.onBackPressed()
 }
diff --git a/src/main/scala/com/github/shadowsocks/ProfileConfigFragment.scala b/src/main/scala/com/github/shadowsocks/ProfileConfigFragment.scala
index 47e03cc2..ce48e26e 100644
--- a/src/main/scala/com/github/shadowsocks/ProfileConfigFragment.scala
+++ b/src/main/scala/com/github/shadowsocks/ProfileConfigFragment.scala
@@ -20,6 +20,7 @@
 
 package com.github.shadowsocks
 
+import android.content.SharedPreferences.OnSharedPreferenceChangeListener
 import android.content._
 import android.os._
 import android.support.v14.preference.SwitchPreference
@@ -34,7 +35,8 @@ import com.github.shadowsocks.database.Profile
 import com.github.shadowsocks.preferences.KcpCliPreferenceDialogFragment
 import com.github.shadowsocks.utils.{Action, Key, Utils}
 
-class ProfileConfigFragment extends PreferenceFragment with OnMenuItemClickListener {
+class ProfileConfigFragment extends PreferenceFragment with OnMenuItemClickListener
+  with OnSharedPreferenceChangeListener {
   private lazy val clipboard = getActivity.getSystemService(Context.CLIPBOARD_SERVICE).asInstanceOf[ClipboardManager]
   private var profile: Profile = _
   private var isProxyApps: SwitchPreference = _
@@ -59,6 +61,15 @@ class ProfileConfigFragment extends PreferenceFragment with OnMenuItemClickListe
       isProxyApps.setChecked(true)
       false
     })
+    app.settings.registerOnSharedPreferenceChangeListener(this)
+  }
+
+  override def onSharedPreferenceChanged(sharedPreferences: SharedPreferences, key: String): Unit =
+    if (findPreference(key) != null) app.editor.putBoolean(Key.dirty, true).apply()
+
+  override def onDestroy() {
+    app.settings.unregisterOnSharedPreferenceChangeListener(this)
+    super.onDestroy()
   }
 
   override def onResume() {
diff --git a/src/main/scala/com/github/shadowsocks/database/Profile.scala b/src/main/scala/com/github/shadowsocks/database/Profile.scala
index b431b1e8..d893bc29 100644
--- a/src/main/scala/com/github/shadowsocks/database/Profile.scala
+++ b/src/main/scala/com/github/shadowsocks/database/Profile.scala
@@ -119,7 +119,7 @@ class Profile {
     .putString(Key.individual, individual)
     .putBoolean(Key.kcp, kcp)
     .putInt(Key.kcpPort, kcpPort)
-    .putString(Key.kcpcli, kcpcli)
+    .remove(Key.dirty)
   def deserialize(pref: SharedPreferences) {
     // It's assumed that default values are never used, so 0/false/null is always used even if that isn't the case
     name = pref.getString(Key.name, null)
diff --git a/src/main/scala/com/github/shadowsocks/utils/Constants.scala b/src/main/scala/com/github/shadowsocks/utils/Constants.scala
index 3e8bfbfc..1da063a5 100644
--- a/src/main/scala/com/github/shadowsocks/utils/Constants.scala
+++ b/src/main/scala/com/github/shadowsocks/utils/Constants.scala
@@ -155,6 +155,8 @@ object Key {
   val kcpPort = "kcpPort"
   val kcpcli = "kcpcli"
 
+  val dirty = "profileDirty"
+
   val tfo = "tcp_fastopen"
   val currentVersionCode = "currentVersionCode"
 }