diff --git a/app/src/main/java/eu/faircode/netguard/ActivityMain.java b/app/src/main/java/eu/faircode/netguard/ActivityMain.java
index 9e904cde..364afda1 100644
--- a/app/src/main/java/eu/faircode/netguard/ActivityMain.java
+++ b/app/src/main/java/eu/faircode/netguard/ActivityMain.java
@@ -875,7 +875,7 @@ public class ActivityMain extends AppCompatActivity implements SharedPreferences
     private void xmlExport(OutputStream out) throws IOException {
         XmlSerializer serializer = Xml.newSerializer();
         serializer.setOutput(out, "UTF-8");
-        serializer.startDocument(null, Boolean.valueOf(true));
+        serializer.startDocument(null, true);
         serializer.setFeature("http://xmlpull.org/v1/doc/features.html#indent-output", true);
         serializer.startTag(null, "netguard");
 
diff --git a/app/src/main/java/eu/faircode/netguard/Receiver.java b/app/src/main/java/eu/faircode/netguard/Receiver.java
index caff113b..d861c3c3 100644
--- a/app/src/main/java/eu/faircode/netguard/Receiver.java
+++ b/app/src/main/java/eu/faircode/netguard/Receiver.java
@@ -22,7 +22,6 @@ package eu.faircode.netguard;
 import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
-import android.content.SharedPreferences;
 import android.net.VpnService;
 import android.util.Log;
 
diff --git a/app/src/main/java/eu/faircode/netguard/Rule.java b/app/src/main/java/eu/faircode/netguard/Rule.java
index 02e94058..d1ba4311 100644
--- a/app/src/main/java/eu/faircode/netguard/Rule.java
+++ b/app/src/main/java/eu/faircode/netguard/Rule.java
@@ -26,7 +26,6 @@ import android.content.pm.ApplicationInfo;
 import android.content.pm.PackageInfo;
 import android.content.pm.PackageManager;
 import android.content.res.XmlResourceParser;
-import android.graphics.drawable.Drawable;
 import android.preference.PreferenceManager;
 import android.util.Log;
 
diff --git a/app/src/main/java/eu/faircode/netguard/RuleAdapter.java b/app/src/main/java/eu/faircode/netguard/RuleAdapter.java
index 2a35918c..84c8acee 100644
--- a/app/src/main/java/eu/faircode/netguard/RuleAdapter.java
+++ b/app/src/main/java/eu/faircode/netguard/RuleAdapter.java
@@ -25,8 +25,6 @@ import android.content.res.TypedArray;
 import android.graphics.Color;
 import android.graphics.Rect;
 import android.net.Uri;
-import android.os.AsyncTask;
-import android.preference.PreferenceManager;
 import android.support.v4.content.ContextCompat;
 import android.support.v7.widget.RecyclerView;
 import android.util.Log;
diff --git a/app/src/main/java/eu/faircode/netguard/Util.java b/app/src/main/java/eu/faircode/netguard/Util.java
index 7f02f88f..4e0f626c 100644
--- a/app/src/main/java/eu/faircode/netguard/Util.java
+++ b/app/src/main/java/eu/faircode/netguard/Util.java
@@ -161,7 +161,7 @@ public class Util {
         AsyncTask task = new AsyncTask<Object, Object, Intent>() {
             @Override
             protected Intent doInBackground(Object... objects) {
-                PackageInfo pInfo = null;
+                PackageInfo pInfo;
                 try {
                     pInfo = context.getPackageManager().getPackageInfo(context.getPackageName(), 0);
                 } catch (PackageManager.NameNotFoundException ex) {