diff --git a/app/src/main/java/org/koitharu/kotatsu/main/ui/protect/ProtectActivity.kt b/app/src/main/java/org/koitharu/kotatsu/main/ui/protect/ProtectActivity.kt
index 97ca1df3a..bf3c865eb 100644
--- a/app/src/main/java/org/koitharu/kotatsu/main/ui/protect/ProtectActivity.kt
+++ b/app/src/main/java/org/koitharu/kotatsu/main/ui/protect/ProtectActivity.kt
@@ -7,6 +7,7 @@ import android.text.Editable
 import android.text.TextWatcher
 import android.view.KeyEvent
 import android.view.View
+import android.view.WindowManager
 import android.view.inputmethod.EditorInfo
 import android.widget.TextView
 import androidx.core.graphics.Insets
@@ -23,6 +24,7 @@ class ProtectActivity : BaseActivity<ActivityProtectBinding>(), TextView.OnEdito
 
 	override fun onCreate(savedInstanceState: Bundle?) {
 		super.onCreate(savedInstanceState)
+		window.addFlags(WindowManager.LayoutParams.FLAG_SECURE)
 		setContentView(ActivityProtectBinding.inflate(layoutInflater))
 		binding.editPassword.setOnEditorActionListener(this)
 		binding.editPassword.addTextChangedListener(this)
diff --git a/app/src/main/java/org/koitharu/kotatsu/settings/protect/ProtectSetupActivity.kt b/app/src/main/java/org/koitharu/kotatsu/settings/protect/ProtectSetupActivity.kt
index 5ab950d69..7ca1f3642 100644
--- a/app/src/main/java/org/koitharu/kotatsu/settings/protect/ProtectSetupActivity.kt
+++ b/app/src/main/java/org/koitharu/kotatsu/settings/protect/ProtectSetupActivity.kt
@@ -5,6 +5,7 @@ import android.text.Editable
 import android.text.TextWatcher
 import android.view.KeyEvent
 import android.view.View
+import android.view.WindowManager
 import android.view.inputmethod.EditorInfo
 import android.widget.TextView
 import androidx.core.graphics.Insets
@@ -21,6 +22,7 @@ class ProtectSetupActivity : BaseActivity<ActivitySetupProtectBinding>(), TextWa
 
 	override fun onCreate(savedInstanceState: Bundle?) {
 		super.onCreate(savedInstanceState)
+		window.addFlags(WindowManager.LayoutParams.FLAG_SECURE)
 		setContentView(ActivitySetupProtectBinding.inflate(layoutInflater))
 		binding.editPassword.addTextChangedListener(this)
 		binding.editPassword.setOnEditorActionListener(this)