diff --git a/Guide.md b/Guide.md
index 4aa9f2c..477fcad 100644
--- a/Guide.md
+++ b/Guide.md
@@ -31,7 +31,7 @@
 
 ## 使用前须知
 
-1. device admin, profile owner和device owner有极高的特权，包括但不限于让你的设备丢失所有数据。所以，请谨慎使用
+1. Device admin, Profile owner和Device owner有极高的特权，包括但不限于让你的设备丢失所有数据。所以，请谨慎使用
 2. 以下的所有命令都需要在`adb shell`中执行。请进入`adb shell`后执行，不要直接`adb shell xxx`，容易出问题
 3. ColorOS用户请在release页面下载testKey版，否则无法激活Device owner
 
@@ -668,9 +668,10 @@ pm list packages
 
 ### 禁止用户控制
 
-需要的权限：Device owner或Profile owner
+需要的权限： Device owner或Profile owner
 
-需要API30或以上
+如果是Device owner，需要API30或以上，如果是Profile owner，需要API33或以上
+（谷歌并没有在文档中说明Profile owner调用此功能所需的API等级，但是，[MinoriceOWO](https://github.com/MinoriceOwO)发现Profile owner在API33以下调用这个功能会导致OwnDroid崩溃[(issue #12)](https://github.com/BinTianqi/OwnDroid/issues/12)。[commit d4e8473](https://github.com/BinTianqi/OwnDroid/commit/d4e8473218a6d91bf3608133061f8e636e48cdbb)中已对API33以下的Profile owner隐藏该功能入口）
 
 用户无法清除这些应用的存储空间和缓存，但是可以在这里清除
 
diff --git a/app/proguard-rules.pro b/app/proguard-rules.pro
index 55542ee..18ebe95 100644
--- a/app/proguard-rules.pro
+++ b/app/proguard-rules.pro
@@ -12,7 +12,6 @@
 #-keepclassmembers class fqcn.of.javascript.interface.for.webview {
 #   public *;
 #}
--keep class com.bintianqi.owndroid.dpm.ShizukuService
 
 # Uncomment this to preserve the line number information for
 # debugging stack traces.
diff --git a/app/src/main/java/com/bintianqi/owndroid/dpm/Permissions.kt b/app/src/main/java/com/bintianqi/owndroid/dpm/Permissions.kt
index 3be1d47..a9a6693 100644
--- a/app/src/main/java/com/bintianqi/owndroid/dpm/Permissions.kt
+++ b/app/src/main/java/com/bintianqi/owndroid/dpm/Permissions.kt
@@ -112,10 +112,12 @@ private fun Home(localNavCtrl:NavHostController,listScrollState:ScrollState){
             R.string.device_admin, stringResource(if(myDpm.isAdminActive(myComponent)){R.string.activated}else{R.string.deactivated}),
             operation = {localNavCtrl.navigate("DeviceAdmin")}
         )
-        SubPageItem(
-            R.string.profile_owner, stringResource(if(isProfileOwner(myDpm)){R.string.activated}else{R.string.deactivated}),
-            operation = {localNavCtrl.navigate("ProfileOwner")}
-        )
+        if(!isDeviceOwner(myDpm)){
+            SubPageItem(
+                R.string.profile_owner, stringResource(if(isProfileOwner(myDpm)){R.string.activated}else{R.string.deactivated}),
+                operation = {localNavCtrl.navigate("ProfileOwner")}
+            )
+        }
         SubPageItem(
             R.string.device_owner, stringResource(if(isDeviceOwner(myDpm)){R.string.activated}else{R.string.deactivated}),
             operation = {localNavCtrl.navigate("DeviceOwner")}
diff --git a/app/src/main/java/com/bintianqi/owndroid/dpm/ShizukuService.kt b/app/src/main/java/com/bintianqi/owndroid/dpm/ShizukuService.kt
index d967578..1a77eeb 100644
--- a/app/src/main/java/com/bintianqi/owndroid/dpm/ShizukuService.kt
+++ b/app/src/main/java/com/bintianqi/owndroid/dpm/ShizukuService.kt
@@ -2,12 +2,14 @@ package com.bintianqi.owndroid.dpm
 
 import android.os.IBinder
 import android.system.Os
+import androidx.annotation.Keep
 import com.bintianqi.owndroid.IUserService
 import java.io.BufferedReader
 import java.io.InputStreamReader
 
 var service:IUserService? = null
 
+@Keep
 class ShizukuService: IUserService.Stub() {
     override fun asBinder(): IBinder {
         TODO("Not yet implemented")