diff --git a/app/src/main/java/se/ajpanton/notificationlog/MainActivity.kt b/app/src/main/java/se/ajpanton/notificationlog/MainActivity.kt
index 8b83fbe..8cf07e4 100644
--- a/app/src/main/java/se/ajpanton/notificationlog/MainActivity.kt
+++ b/app/src/main/java/se/ajpanton/notificationlog/MainActivity.kt
@@ -39,6 +39,7 @@ class MainActivity : AppCompatActivity(), NavigationView.OnNavigationItemSelecte
         WindowCompat.setDecorFitsSystemWindows(window, true)
         binding = ActivityMainBinding.inflate(layoutInflater)
         setContentView(binding.root)
+        showLockedOverlay(AppLockStore(this).enabled)
         val isNightMode = resources.configuration.uiMode and Configuration.UI_MODE_NIGHT_MASK ==
             Configuration.UI_MODE_NIGHT_YES
         WindowInsetsControllerCompat(window, binding.root).isAppearanceLightNavigationBars = !isNightMode
@@ -84,12 +85,20 @@ class MainActivity : AppCompatActivity(), NavigationView.OnNavigationItemSelecte
 
     override fun onResume() {
         super.onResume()
-        if (needsUnlock && AppLockStore(this).enabled) requestUnlock()
+        if (needsUnlock && AppLockStore(this).enabled) {
+            showLockedOverlay(true)
+            requestUnlock()
+        } else {
+            showLockedOverlay(false)
+        }
     }
 
     override fun onStop() {
         super.onStop()
-        if (!isChangingConfigurations) needsUnlock = true
+        if (!isChangingConfigurations) {
+            needsUnlock = true
+            if (AppLockStore(this).enabled) showLockedOverlay(true)
+        }
     }
 
     private fun requestUnlock() {
@@ -98,11 +107,18 @@ class MainActivity : AppCompatActivity(), NavigationView.OnNavigationItemSelecte
             .setAllowedAuthenticators(Authenticators.BIOMETRIC_STRONG or Authenticators.DEVICE_CREDENTIAL)
             .build()
             .authenticate(CancellationSignal(), mainExecutor, object : BiometricPrompt.AuthenticationCallback() {
-                override fun onAuthenticationSucceeded(result: BiometricPrompt.AuthenticationResult?) { needsUnlock = false }
+                override fun onAuthenticationSucceeded(result: BiometricPrompt.AuthenticationResult?) {
+                    needsUnlock = false
+                    showLockedOverlay(false)
+                }
                 override fun onAuthenticationError(errorCode: Int, errString: CharSequence?) { finishAndRemoveTask() }
             })
     }
 
+    private fun showLockedOverlay(visible: Boolean) {
+        binding.lockOverlay.visibility = if (visible) View.VISIBLE else View.GONE
+    }
+
     override fun onNavigationItemSelected(item: MenuItem): Boolean {
         navigateTo(item.itemId)
         if (!permanentSidebar) {
diff --git a/app/src/main/res/layout/activity_main.xml b/app/src/main/res/layout/activity_main.xml
index e621f92..0432a0f 100644
--- a/app/src/main/res/layout/activity_main.xml
+++ b/app/src/main/res/layout/activity_main.xml
@@ -1,5 +1,9 @@
 <?xml version="1.0" encoding="utf-8"?>
-<se.ajpanton.notificationlog.SafeInsetDrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+<se.ajpanton.notificationlog.SafeInsetDrawerLayout
     xmlns:app="http://schemas.android.com/apk/res-auto"
     android:id="@+id/drawer_layout"
     android:layout_width="match_parent"
@@ -61,3 +65,22 @@
         app:menu="@menu/drawer_menu" />
 
 </se.ajpanton.notificationlog.SafeInsetDrawerLayout>
+
+    <LinearLayout
+        android:id="@+id/lock_overlay"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:background="@color/window_background"
+        android:clickable="true"
+        android:focusable="true"
+        android:gravity="center"
+        android:orientation="vertical"
+        android:visibility="gone">
+
+        <TextView
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:text="Notification Log is locked"
+            android:textAppearance="?attr/textAppearanceHeadline6" />
+    </LinearLayout>
+</FrameLayout>