diff --git a/FAQ.md b/FAQ.md
index 6c53a00353..0cafa44a31 100644
--- a/FAQ.md
+++ b/FAQ.md
@@ -1897,7 +1897,7 @@ for a list of privacy friendly email providers with advantages and disadvantages
 **(113) How does biometric authentication work?**
 
 If your device has a biometric sensor, for example a fingerprint sensor, you can enable/disable biometric authentication in the navigation (hamburger) menu of the setup screen.
-When enabled FairEmail will require biometric authentication after a period of inactivity or after the screen has been turned off while FairEmail was visible.
+When enabled FairEmail will require biometric authentication after a period of inactivity or after the screen has been turned off while FairEmail was running.
 Activity is navigation within FairEmail, for example opening a conversation thread.
 When biometric authentication is enabled only a summary notification with the number of new messages will be shown, so all message content is hidden.
 
diff --git a/app/src/main/java/eu/faircode/email/ServiceSynchronize.java b/app/src/main/java/eu/faircode/email/ServiceSynchronize.java
index 3f8583a1bf..34bef0fdfe 100644
--- a/app/src/main/java/eu/faircode/email/ServiceSynchronize.java
+++ b/app/src/main/java/eu/faircode/email/ServiceSynchronize.java
@@ -127,7 +127,9 @@ public class ServiceSynchronize extends LifecycleService {
         builder.addCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET);
         // Removed because of Android VPN service
         // builder.addCapability(NetworkCapabilities.NET_CAPABILITY_VALIDATED);
-        cm.registerNetworkCallback(builder.build(), networkCallback);
+        cm.registerNetworkCallback(builder.build(), onNetworkCallback);
+
+        registerReceiver(onScreenOff, new IntentFilter(Intent.ACTION_SCREEN_OFF));
 
         DB db = DB.getInstance(this);
 
@@ -183,6 +185,8 @@ public class ServiceSynchronize extends LifecycleService {
         });
 
         WorkerCleanup.queue(this);
+
+
     }
 
     @Override
@@ -190,8 +194,10 @@ public class ServiceSynchronize extends LifecycleService {
         Log.i("Service destroy");
         EntityLog.log(this, "Service destroy");
 
+        unregisterReceiver(onScreenOff);
+
         ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
-        cm.unregisterNetworkCallback(networkCallback);
+        cm.unregisterNetworkCallback(onNetworkCallback);
 
         Core.notifyReset(this);
 
@@ -1265,7 +1271,7 @@ public class ServiceSynchronize extends LifecycleService {
         }
     }
 
-    ConnectivityManager.NetworkCallback networkCallback = new ConnectivityManager.NetworkCallback() {
+    private ConnectivityManager.NetworkCallback onNetworkCallback = new ConnectivityManager.NetworkCallback() {
         @Override
         public void onAvailable(Network network) {
             networkState.update(ConnectionHelper.getNetworkState(ServiceSynchronize.this));
@@ -1357,6 +1363,15 @@ public class ServiceSynchronize extends LifecycleService {
         }
     };
 
+    private BroadcastReceiver onScreenOff = new BroadcastReceiver() {
+        @Override
+        public void onReceive(Context context, Intent intent) {
+            Log.i("Received " + intent);
+            Log.logExtras(intent);
+            Helper.clearAuthentication(ServiceSynchronize.this);
+        }
+    };
+
     static void boot(final Context context) {
         if (!booted) {
             booted = true;