diff --git a/app/src/main/java/org/itxtech/daedalus/activity/MainActivity.java b/app/src/main/java/org/itxtech/daedalus/activity/MainActivity.java
index eafb137..2b55164 100644
--- a/app/src/main/java/org/itxtech/daedalus/activity/MainActivity.java
+++ b/app/src/main/java/org/itxtech/daedalus/activity/MainActivity.java
@@ -127,6 +127,7 @@ public class MainActivity extends AppCompatActivity implements NavigationView.On
 
         Log.d(TAG, "onDestroy");
         instance = null;
+        currentFragment = null;
     }
 
     @Override
diff --git a/app/src/main/java/org/itxtech/daedalus/fragment/SettingsFragment.java b/app/src/main/java/org/itxtech/daedalus/fragment/SettingsFragment.java
index 13d0aa1..41e1620 100644
--- a/app/src/main/java/org/itxtech/daedalus/fragment/SettingsFragment.java
+++ b/app/src/main/java/org/itxtech/daedalus/fragment/SettingsFragment.java
@@ -1,6 +1,7 @@
 package org.itxtech.daedalus.fragment;
 
 import android.app.FragmentManager;
+import android.os.Build;
 import android.os.Bundle;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -27,7 +28,12 @@ public class SettingsFragment extends ToolbarFragment {
     @Override
     public void onViewCreated(View view, Bundle savedInstanceState) {
         super.onViewCreated(view, savedInstanceState);
-        FragmentManager fm = getFragmentManager();
+        FragmentManager fm;
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
+            fm = getChildFragmentManager();
+        } else {
+            fm = getFragmentManager();
+        }
         fm.beginTransaction().replace(R.id.settings_content, new GlobalConfigFragment()).commit();
     }