diff --git a/app/src/main/java/org/itxtech/daedalus/fragment/RuleConfigFragment.java b/app/src/main/java/org/itxtech/daedalus/fragment/RuleConfigFragment.java
index 883eddf..860c83c 100644
--- a/app/src/main/java/org/itxtech/daedalus/fragment/RuleConfigFragment.java
+++ b/app/src/main/java/org/itxtech/daedalus/fragment/RuleConfigFragment.java
@@ -1,11 +1,9 @@
 package org.itxtech.daedalus.fragment;
 
-import android.annotation.TargetApi;
 import android.app.Activity;
 import android.app.AlertDialog;
 import android.content.Intent;
 import android.net.Uri;
-import android.os.Build;
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.Message;
@@ -224,7 +222,6 @@ public class RuleConfigFragment extends ConfigFragment {
         return view;
     }
 
-    @TargetApi(Build.VERSION_CODES.KITKAT)
     private void performFileSearch() {
         Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT);
 
@@ -237,7 +234,6 @@ public class RuleConfigFragment extends ConfigFragment {
     }
 
     @Override
-    @TargetApi(Build.VERSION_CODES.KITKAT)
     public void onActivityResult(int requestCode, int resultCode, Intent resultData) {
         if (requestCode == READ_REQUEST_CODE && resultCode == Activity.RESULT_OK) {
             if (resultData != null) {
diff --git a/app/src/main/java/org/itxtech/daedalus/provider/HttpsProvider.java b/app/src/main/java/org/itxtech/daedalus/provider/HttpsProvider.java
index b9b7a80..2acb812 100644
--- a/app/src/main/java/org/itxtech/daedalus/provider/HttpsProvider.java
+++ b/app/src/main/java/org/itxtech/daedalus/provider/HttpsProvider.java
@@ -1,7 +1,5 @@
 package org.itxtech.daedalus.provider;
 
-import android.annotation.TargetApi;
-import android.os.Build;
 import android.os.ParcelFileDescriptor;
 import android.system.Os;
 import android.system.OsConstants;
@@ -68,7 +66,6 @@ abstract public class HttpsProvider extends Provider {
                 .build();
     }
 
-    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
     public void process() {
         try {
             FileDescriptor[] pipes = Os.pipe();
diff --git a/app/src/main/java/org/itxtech/daedalus/provider/Provider.java b/app/src/main/java/org/itxtech/daedalus/provider/Provider.java
index 4a9d681..3e623ef 100644
--- a/app/src/main/java/org/itxtech/daedalus/provider/Provider.java
+++ b/app/src/main/java/org/itxtech/daedalus/provider/Provider.java
@@ -1,7 +1,5 @@
 package org.itxtech.daedalus.provider;
 
-import android.annotation.TargetApi;
-import android.os.Build;
 import android.os.ParcelFileDescriptor;
 import android.system.Os;
 import org.itxtech.daedalus.Daedalus;
@@ -65,7 +63,6 @@ public abstract class Provider {
         running = false;
     }
 
-    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
     public void stop() {
         try {
             if (mInterruptFd != null) {
@@ -189,4 +186,4 @@ public abstract class Provider {
     }
 
     protected abstract void handleDnsRequest(byte[] packetData) throws DaedalusVpnService.VpnNetworkException;
-}
\ No newline at end of file
+}
diff --git a/app/src/main/java/org/itxtech/daedalus/provider/TcpProvider.java b/app/src/main/java/org/itxtech/daedalus/provider/TcpProvider.java
index 202fca5..3768ea5 100644
--- a/app/src/main/java/org/itxtech/daedalus/provider/TcpProvider.java
+++ b/app/src/main/java/org/itxtech/daedalus/provider/TcpProvider.java
@@ -1,7 +1,5 @@
 package org.itxtech.daedalus.provider;
 
-import android.annotation.TargetApi;
-import android.os.Build;
 import android.os.ParcelFileDescriptor;
 import android.system.ErrnoException;
 import android.system.Os;
@@ -44,7 +42,6 @@ public class TcpProvider extends UdpProvider {
         super(descriptor, service);
     }
 
-    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
     public void process() {
         try {
             FileDescriptor[] pipes = Os.pipe();
diff --git a/app/src/main/java/org/itxtech/daedalus/provider/UdpProvider.java b/app/src/main/java/org/itxtech/daedalus/provider/UdpProvider.java
index cba4ed6..c51f5d3 100644
--- a/app/src/main/java/org/itxtech/daedalus/provider/UdpProvider.java
+++ b/app/src/main/java/org/itxtech/daedalus/provider/UdpProvider.java
@@ -1,7 +1,5 @@
 package org.itxtech.daedalus.provider;
 
-import android.annotation.TargetApi;
-import android.os.Build;
 import android.os.ParcelFileDescriptor;
 import android.system.Os;
 import android.system.OsConstants;
@@ -47,7 +45,6 @@ public class UdpProvider extends Provider {
         super(descriptor, service);
     }
 
-    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
     public void process() {
         try {
             FileDescriptor[] pipes = Os.pipe();
diff --git a/app/src/main/java/org/itxtech/daedalus/service/DaedalusVpnService.java b/app/src/main/java/org/itxtech/daedalus/service/DaedalusVpnService.java
index 62af8b8..7daf8f8 100644
--- a/app/src/main/java/org/itxtech/daedalus/service/DaedalusVpnService.java
+++ b/app/src/main/java/org/itxtech/daedalus/service/DaedalusVpnService.java
@@ -1,6 +1,5 @@
 package org.itxtech.daedalus.service;
 
-import android.annotation.TargetApi;
 import android.app.Notification;
 import android.app.NotificationChannel;
 import android.app.NotificationManager;
@@ -153,7 +152,6 @@ public class DaedalusVpnService extends VpnService implements Runnable {
         stopThread();
     }
 
-    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
     private void stopThread() {
         Log.d(TAG, "stopThread");
         activated = false;
@@ -231,7 +229,6 @@ public class DaedalusVpnService extends VpnService implements Runnable {
         return null;
     }
 
-    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
     @Override
     public void run() {
         try {
diff --git a/app/src/main/java/org/itxtech/daedalus/widget/ClickPreference.java b/app/src/main/java/org/itxtech/daedalus/widget/ClickPreference.java
index 4553233..432bc04 100644
--- a/app/src/main/java/org/itxtech/daedalus/widget/ClickPreference.java
+++ b/app/src/main/java/org/itxtech/daedalus/widget/ClickPreference.java
@@ -1,8 +1,6 @@
 package org.itxtech.daedalus.widget;
 
-import android.annotation.TargetApi;
 import android.content.Context;
-import android.os.Build;
 import android.preference.ListPreference;
 import android.util.AttributeSet;
 
@@ -19,7 +17,6 @@ import android.util.AttributeSet;
  */
 public class ClickPreference extends ListPreference {
 
-    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
     public ClickPreference(Context context, AttributeSet attrs, int defStyleAttr) {
         super(context, attrs, defStyleAttr);
     }