diff --git a/packages/SystemUI/res-keyguard/values/strings.xml b/packages/SystemUI/res-keyguard/values/strings.xml
index 28f5f3d9edd7a..badad584824b8 100644
--- a/packages/SystemUI/res-keyguard/values/strings.xml
+++ b/packages/SystemUI/res-keyguard/values/strings.xml
@@ -358,12 +358,12 @@
     <!-- Message shown to prepare for an unattended update (OTA). Also known as an over-the-air (OTA) update.  [CHAR LIMIT=70] -->
     <string name="kg_prompt_unattended_update_pattern">Draw pattern to install update later</string>
 
-    <!-- Message shown after an unattended update (OTA) asking the user to enter their PIN. Also known as an over-the-air (OTA) update.  [CHAR LIMIT=70] -->
+    <!--  Message shown after an unattended mainline (major) update asking the user to enter their PIN. [CHAR LIMIT=70] -->
     <string name="kg_prompt_after_update_pin">Device updated. Enter PIN to continue.</string>
 
-    <!-- Message shown after an unattended update (OTA) asking the user to enter their password. Also known as an over-the-air (OTA) update.  [CHAR LIMIT=70] -->
+    <!-- Message shown after an unattended mainline (major) update asking the user to enter their password. [CHAR LIMIT=70] -->
     <string name="kg_prompt_after_update_password">Device updated. Enter password to continue.</string>
 
-    <!-- Message shown after an unattended update (OTA) asking the user to enter their pattern. Also known as an over-the-air (OTA) update.  [CHAR LIMIT=70] -->
+    <!-- Message shown after an unattended mainline (major) update asking the user to enter their pattern. [CHAR LIMIT=70] -->
     <string name="kg_prompt_after_update_pattern">Device updated. Draw pattern to continue.</string>
 </resources>
diff --git a/packages/SystemUI/src/com/android/keyguard/KeyguardPasswordView.java b/packages/SystemUI/src/com/android/keyguard/KeyguardPasswordView.java
index 7a0a24a85eaf0..03d9eb3455fdb 100644
--- a/packages/SystemUI/src/com/android/keyguard/KeyguardPasswordView.java
+++ b/packages/SystemUI/src/com/android/keyguard/KeyguardPasswordView.java
@@ -23,6 +23,7 @@ import static com.android.keyguard.KeyguardSecurityView.PROMPT_REASON_NONE;
 import static com.android.keyguard.KeyguardSecurityView.PROMPT_REASON_NON_STRONG_BIOMETRIC_TIMEOUT;
 import static com.android.keyguard.KeyguardSecurityView.PROMPT_REASON_PREPARE_FOR_UPDATE;
 import static com.android.keyguard.KeyguardSecurityView.PROMPT_REASON_RESTART;
+import static com.android.keyguard.KeyguardSecurityView.PROMPT_REASON_RESTART_FOR_MAINLINE_UPDATE;
 import static com.android.keyguard.KeyguardSecurityView.PROMPT_REASON_TIMEOUT;
 import static com.android.keyguard.KeyguardSecurityView.PROMPT_REASON_TRUSTAGENT_EXPIRED;
 import static com.android.keyguard.KeyguardSecurityView.PROMPT_REASON_USER_REQUEST;
@@ -99,6 +100,8 @@ public class KeyguardPasswordView extends KeyguardAbsKeyInputView {
         switch (reason) {
             case PROMPT_REASON_RESTART:
                 return R.string.kg_prompt_reason_restart_password;
+            case PROMPT_REASON_RESTART_FOR_MAINLINE_UPDATE:
+                return R.string.kg_prompt_after_update_password;
             case PROMPT_REASON_TIMEOUT:
                 return R.string.kg_prompt_reason_timeout_password;
             case PROMPT_REASON_DEVICE_ADMIN:
@@ -106,7 +109,7 @@ public class KeyguardPasswordView extends KeyguardAbsKeyInputView {
             case PROMPT_REASON_USER_REQUEST:
                 return R.string.kg_prompt_after_user_lockdown_password;
             case PROMPT_REASON_PREPARE_FOR_UPDATE:
-                return R.string.kg_prompt_reason_timeout_password;
+                return R.string.kg_prompt_unattended_update_password;
             case PROMPT_REASON_NON_STRONG_BIOMETRIC_TIMEOUT:
                 return R.string.kg_prompt_reason_timeout_password;
             case PROMPT_REASON_TRUSTAGENT_EXPIRED:
diff --git a/packages/SystemUI/src/com/android/keyguard/KeyguardPatternViewController.java b/packages/SystemUI/src/com/android/keyguard/KeyguardPatternViewController.java
index ffb28b05e7002..ad9fea6432da1 100644
--- a/packages/SystemUI/src/com/android/keyguard/KeyguardPatternViewController.java
+++ b/packages/SystemUI/src/com/android/keyguard/KeyguardPatternViewController.java
@@ -304,6 +304,9 @@ public class KeyguardPatternViewController
             case PROMPT_REASON_RESTART:
                 resId = R.string.kg_prompt_reason_restart_pattern;
                 break;
+            case PROMPT_REASON_RESTART_FOR_MAINLINE_UPDATE:
+                resId = R.string.kg_prompt_after_update_pattern;
+                break;
             case PROMPT_REASON_TIMEOUT:
                 resId = R.string.kg_prompt_reason_timeout_pattern;
                 break;
@@ -314,7 +317,7 @@ public class KeyguardPatternViewController
                 resId = R.string.kg_prompt_after_user_lockdown_pattern;
                 break;
             case PROMPT_REASON_PREPARE_FOR_UPDATE:
-                resId = R.string.kg_prompt_reason_timeout_pattern;
+                resId = R.string.kg_prompt_unattended_update_pattern;
                 break;
             case PROMPT_REASON_NON_STRONG_BIOMETRIC_TIMEOUT:
                 resId = R.string.kg_prompt_reason_timeout_pattern;
diff --git a/packages/SystemUI/src/com/android/keyguard/KeyguardPinBasedInputView.java b/packages/SystemUI/src/com/android/keyguard/KeyguardPinBasedInputView.java
index 687436c5d3884..38e5dc57d3163 100644
--- a/packages/SystemUI/src/com/android/keyguard/KeyguardPinBasedInputView.java
+++ b/packages/SystemUI/src/com/android/keyguard/KeyguardPinBasedInputView.java
@@ -21,6 +21,7 @@ import static com.android.keyguard.KeyguardSecurityView.PROMPT_REASON_NONE;
 import static com.android.keyguard.KeyguardSecurityView.PROMPT_REASON_NON_STRONG_BIOMETRIC_TIMEOUT;
 import static com.android.keyguard.KeyguardSecurityView.PROMPT_REASON_PREPARE_FOR_UPDATE;
 import static com.android.keyguard.KeyguardSecurityView.PROMPT_REASON_RESTART;
+import static com.android.keyguard.KeyguardSecurityView.PROMPT_REASON_RESTART_FOR_MAINLINE_UPDATE;
 import static com.android.keyguard.KeyguardSecurityView.PROMPT_REASON_TIMEOUT;
 import static com.android.keyguard.KeyguardSecurityView.PROMPT_REASON_TRUSTAGENT_EXPIRED;
 import static com.android.keyguard.KeyguardSecurityView.PROMPT_REASON_USER_REQUEST;
@@ -113,6 +114,8 @@ public abstract class KeyguardPinBasedInputView extends KeyguardAbsKeyInputView
         switch (reason) {
             case PROMPT_REASON_RESTART:
                 return R.string.kg_prompt_reason_restart_pin;
+            case PROMPT_REASON_RESTART_FOR_MAINLINE_UPDATE:
+                return R.string.kg_prompt_after_update_pin;
             case PROMPT_REASON_TIMEOUT:
                 return R.string.kg_prompt_reason_timeout_pin;
             case PROMPT_REASON_DEVICE_ADMIN:
@@ -120,7 +123,7 @@ public abstract class KeyguardPinBasedInputView extends KeyguardAbsKeyInputView
             case PROMPT_REASON_USER_REQUEST:
                 return R.string.kg_prompt_after_user_lockdown_pin;
             case PROMPT_REASON_PREPARE_FOR_UPDATE:
-                return R.string.kg_prompt_reason_timeout_pin;
+                return R.string.kg_prompt_unattended_update_pin;
             case PROMPT_REASON_NON_STRONG_BIOMETRIC_TIMEOUT:
                 return R.string.kg_prompt_reason_timeout_pin;
             case PROMPT_REASON_TRUSTAGENT_EXPIRED:
diff --git a/packages/SystemUI/src/com/android/keyguard/KeyguardSecurityView.java b/packages/SystemUI/src/com/android/keyguard/KeyguardSecurityView.java
index 419303d71f97b..21960e219fc93 100644
--- a/packages/SystemUI/src/com/android/keyguard/KeyguardSecurityView.java
+++ b/packages/SystemUI/src/com/android/keyguard/KeyguardSecurityView.java
@@ -102,6 +102,12 @@ public interface KeyguardSecurityView {
      */
     int PROMPT_REASON_PRIMARY_AUTH_LOCKED_OUT = 15;
 
+    /**
+     * Strong auth is required because the device has just booted because of an automatic
+     * mainline update.
+     */
+    int PROMPT_REASON_RESTART_FOR_MAINLINE_UPDATE = 16;
+
     /**
      * Reset the view and prepare to take input. This should do things like clearing the
      * password or pattern and clear error messages.
diff --git a/packages/SystemUI/src/com/android/systemui/keyguard/KeyguardViewMediator.java b/packages/SystemUI/src/com/android/systemui/keyguard/KeyguardViewMediator.java
index e7581255bebc6..8a73d9bd7669f 100644
--- a/packages/SystemUI/src/com/android/systemui/keyguard/KeyguardViewMediator.java
+++ b/packages/SystemUI/src/com/android/systemui/keyguard/KeyguardViewMediator.java
@@ -138,6 +138,7 @@ import com.android.systemui.dreams.DreamOverlayStateController;
 import com.android.systemui.dump.DumpManager;
 import com.android.systemui.flags.FeatureFlags;
 import com.android.systemui.flags.Flags;
+import com.android.systemui.flags.SystemPropertiesHelper;
 import com.android.systemui.keyguard.dagger.KeyguardModule;
 import com.android.systemui.keyguard.ui.viewmodel.DreamingToLockscreenTransitionViewModel;
 import com.android.systemui.log.SessionTracker;
@@ -171,6 +172,7 @@ import dagger.Lazy;
 import java.io.PrintWriter;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Objects;
 import java.util.concurrent.Executor;
 import java.util.function.Consumer;
 
@@ -284,6 +286,8 @@ public class KeyguardViewMediator implements CoreStartable, Dumpable,
      * keyguard to show even if it is disabled for the current user.
      */
     public static final String OPTION_FORCE_SHOW = "force_show";
+    public static final String SYS_BOOT_REASON_PROP = "sys.boot.reason.last";
+    public static final String REBOOT_MAINLINE_UPDATE = "reboot,mainline_update";
     private final DreamOverlayStateController mDreamOverlayStateController;
 
     /** The stream type that the lock sounds are tied to. */
@@ -322,6 +326,7 @@ public class KeyguardViewMediator implements CoreStartable, Dumpable,
     private final SecureSettings mSecureSettings;
     private final SystemSettings mSystemSettings;
     private final SystemClock mSystemClock;
+    private SystemPropertiesHelper mSystemPropertiesHelper;
 
     /**
      * Used to keep the device awake while to ensure the keyguard finishes opening before
@@ -853,7 +858,12 @@ public class KeyguardViewMediator implements CoreStartable, Dumpable,
                     strongAuthTracker.isNonStrongBiometricAllowedAfterIdleTimeout(currentUser);
 
             if (any && !strongAuthTracker.hasUserAuthenticatedSinceBoot()) {
-                return KeyguardSecurityView.PROMPT_REASON_RESTART;
+                String reasonForReboot = mSystemPropertiesHelper.get(SYS_BOOT_REASON_PROP);
+                if (Objects.equals(reasonForReboot, REBOOT_MAINLINE_UPDATE)) {
+                    return KeyguardSecurityView.PROMPT_REASON_RESTART_FOR_MAINLINE_UPDATE;
+                } else {
+                    return  KeyguardSecurityView.PROMPT_REASON_RESTART;
+                }
             } else if (any && (strongAuth & STRONG_AUTH_REQUIRED_AFTER_TIMEOUT) != 0) {
                 return KeyguardSecurityView.PROMPT_REASON_TIMEOUT;
             } else if (any && (strongAuth & STRONG_AUTH_REQUIRED_AFTER_USER_LOCKDOWN) != 0) {
@@ -1314,7 +1324,8 @@ public class KeyguardViewMediator implements CoreStartable, Dumpable,
             SystemSettings systemSettings,
             SystemClock systemClock,
             @Main CoroutineDispatcher mainDispatcher,
-            Lazy<DreamingToLockscreenTransitionViewModel> dreamingToLockscreenTransitionViewModel) {
+            Lazy<DreamingToLockscreenTransitionViewModel> dreamingToLockscreenTransitionViewModel,
+            SystemPropertiesHelper systemPropertiesHelper) {
         mContext = context;
         mUserTracker = userTracker;
         mFalsingCollector = falsingCollector;
@@ -1331,6 +1342,7 @@ public class KeyguardViewMediator implements CoreStartable, Dumpable,
         mSecureSettings = secureSettings;
         mSystemSettings = systemSettings;
         mSystemClock = systemClock;
+        mSystemPropertiesHelper = systemPropertiesHelper;
         mStatusBarService = IStatusBarService.Stub.asInterface(
                 ServiceManager.getService(Context.STATUS_BAR_SERVICE));
         mKeyguardDisplayManager = keyguardDisplayManager;
diff --git a/packages/SystemUI/src/com/android/systemui/keyguard/dagger/KeyguardModule.java b/packages/SystemUI/src/com/android/systemui/keyguard/dagger/KeyguardModule.java
index 6d6205cde53fe..61bacbda98a53 100644
--- a/packages/SystemUI/src/com/android/systemui/keyguard/dagger/KeyguardModule.java
+++ b/packages/SystemUI/src/com/android/systemui/keyguard/dagger/KeyguardModule.java
@@ -42,6 +42,7 @@ import com.android.systemui.dagger.qualifiers.UiBackground;
 import com.android.systemui.dreams.DreamOverlayStateController;
 import com.android.systemui.dump.DumpManager;
 import com.android.systemui.flags.FeatureFlags;
+import com.android.systemui.flags.SystemPropertiesHelper;
 import com.android.systemui.keyguard.DismissCallbackRegistry;
 import com.android.systemui.keyguard.KeyguardUnlockAnimationController;
 import com.android.systemui.keyguard.KeyguardViewMediator;
@@ -140,7 +141,8 @@ public class KeyguardModule {
             SystemSettings systemSettings,
             SystemClock systemClock,
             @Main CoroutineDispatcher mainDispatcher,
-            Lazy<DreamingToLockscreenTransitionViewModel> dreamingToLockscreenTransitionViewModel) {
+            Lazy<DreamingToLockscreenTransitionViewModel> dreamingToLockscreenTransitionViewModel,
+            SystemPropertiesHelper systemPropertiesHelper) {
         return new KeyguardViewMediator(
                 context,
                 uiEventLogger,
@@ -179,7 +181,8 @@ public class KeyguardModule {
                 systemSettings,
                 systemClock,
                 mainDispatcher,
-                dreamingToLockscreenTransitionViewModel);
+                dreamingToLockscreenTransitionViewModel,
+                systemPropertiesHelper);
     }
 
     /** */
diff --git a/packages/SystemUI/tests/src/com/android/systemui/keyguard/KeyguardViewMediatorTest.java b/packages/SystemUI/tests/src/com/android/systemui/keyguard/KeyguardViewMediatorTest.java
index b1b77acd3113d..350b5e20ab611 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/keyguard/KeyguardViewMediatorTest.java
+++ b/packages/SystemUI/tests/src/com/android/systemui/keyguard/KeyguardViewMediatorTest.java
@@ -27,6 +27,8 @@ import static com.android.internal.widget.LockPatternUtils.StrongAuthTracker.STR
 import static com.android.internal.widget.LockPatternUtils.StrongAuthTracker.STRONG_AUTH_REQUIRED_AFTER_USER_LOCKDOWN;
 import static com.android.systemui.keyguard.KeyguardViewMediator.DELAYED_KEYGUARD_ACTION;
 import static com.android.systemui.keyguard.KeyguardViewMediator.KEYGUARD_LOCK_AFTER_DELAY_DEFAULT;
+import static com.android.systemui.keyguard.KeyguardViewMediator.REBOOT_MAINLINE_UPDATE;
+import static com.android.systemui.keyguard.KeyguardViewMediator.SYS_BOOT_REASON_PROP;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
@@ -80,6 +82,7 @@ import com.android.systemui.dreams.DreamOverlayStateController;
 import com.android.systemui.dump.DumpManager;
 import com.android.systemui.flags.FakeFeatureFlags;
 import com.android.systemui.flags.Flags;
+import com.android.systemui.flags.SystemPropertiesHelper;
 import com.android.systemui.keyguard.ui.viewmodel.DreamingToLockscreenTransitionViewModel;
 import com.android.systemui.log.SessionTracker;
 import com.android.systemui.navigationbar.NavigationModeController;
@@ -179,6 +182,7 @@ public class KeyguardViewMediatorTest extends SysuiTestCase {
 
     private @Mock CoroutineDispatcher mDispatcher;
     private @Mock DreamingToLockscreenTransitionViewModel mDreamingToLockscreenTransitionViewModel;
+    private @Mock SystemPropertiesHelper mSystemPropertiesHelper;
 
     private FakeFeatureFlags mFeatureFlags;
     private int mInitialUserId;
@@ -380,6 +384,23 @@ public class KeyguardViewMediatorTest extends SysuiTestCase {
                 mViewMediator.mViewMediatorCallback.getBouncerPromptReason());
     }
 
+    @Test
+    public void testBouncerPrompt_deviceRestartedDueToMainlineUpdate() {
+        // GIVEN biometrics enrolled
+        when(mUpdateMonitor.isUnlockingWithBiometricsPossible(anyInt())).thenReturn(true);
+
+        // WHEN reboot caused by ota update
+        KeyguardUpdateMonitor.StrongAuthTracker strongAuthTracker =
+                mock(KeyguardUpdateMonitor.StrongAuthTracker.class);
+        when(mUpdateMonitor.getStrongAuthTracker()).thenReturn(strongAuthTracker);
+        when(strongAuthTracker.hasUserAuthenticatedSinceBoot()).thenReturn(false);
+        when(mSystemPropertiesHelper.get(SYS_BOOT_REASON_PROP)).thenReturn(REBOOT_MAINLINE_UPDATE);
+
+        // THEN the bouncer prompt reason should return PROMPT_REASON_RESTART_FOR_OTA
+        assertEquals(KeyguardSecurityView.PROMPT_REASON_RESTART_FOR_MAINLINE_UPDATE,
+                mViewMediator.mViewMediatorCallback.getBouncerPromptReason());
+    }
+
     @Test
     public void testBouncerPrompt_afterUserLockDown() {
         // GIVEN biometrics enrolled
@@ -747,7 +768,8 @@ public class KeyguardViewMediatorTest extends SysuiTestCase {
                 mSystemSettings,
                 mSystemClock,
                 mDispatcher,
-                () -> mDreamingToLockscreenTransitionViewModel);
+                () -> mDreamingToLockscreenTransitionViewModel,
+                mSystemPropertiesHelper);
         mViewMediator.start();
 
         mViewMediator.registerCentralSurfaces(mCentralSurfaces, null, null, null, null, null);