diff --git a/packages/SystemUI/src/com/android/systemui/user/data/repository/UserRepository.kt b/packages/SystemUI/src/com/android/systemui/user/data/repository/UserRepository.kt
index e5ab47325229d..5cf01af92dcd7 100644
--- a/packages/SystemUI/src/com/android/systemui/user/data/repository/UserRepository.kt
+++ b/packages/SystemUI/src/com/android/systemui/user/data/repository/UserRepository.kt
@@ -76,6 +76,9 @@ interface UserRepository {
     /** Whether user switching is currently in progress. */
     val userSwitchingInProgress: Flow<Boolean>
 
+    /** User ID of the main user. */
+    val mainUserId: Int
+
     /** User ID of the last non-guest selected user. */
     val lastSelectedNonGuestUserId: Int
 
@@ -130,7 +133,9 @@ constructor(
     private val _selectedUserInfo = MutableStateFlow<UserInfo?>(null)
     override val selectedUserInfo: Flow<UserInfo> = _selectedUserInfo.filterNotNull()
 
-    override var lastSelectedNonGuestUserId: Int = UserHandle.USER_SYSTEM
+    override var mainUserId: Int = UserHandle.USER_NULL
+        private set
+    override var lastSelectedNonGuestUserId: Int = UserHandle.USER_NULL
         private set
 
     override val isGuestUserAutoCreated: Boolean =
@@ -172,6 +177,11 @@ constructor(
                         // The guest user is always last, regardless of creation time.
                         .sortedBy { it.isGuest }
             }
+
+            if (mainUserId == UserHandle.USER_NULL) {
+                val mainUser = withContext(backgroundDispatcher) { manager.mainUser }
+                mainUser?.let { mainUserId = it.identifier }
+            }
         }
     }
 
diff --git a/packages/SystemUI/src/com/android/systemui/user/domain/interactor/GuestUserInteractor.kt b/packages/SystemUI/src/com/android/systemui/user/domain/interactor/GuestUserInteractor.kt
index a3748852a6160..0a07439e18765 100644
--- a/packages/SystemUI/src/com/android/systemui/user/domain/interactor/GuestUserInteractor.kt
+++ b/packages/SystemUI/src/com/android/systemui/user/domain/interactor/GuestUserInteractor.kt
@@ -139,11 +139,11 @@ constructor(
         }
 
         applicationScope.launch {
-            var newUserId = UserHandle.USER_SYSTEM
+            var newUserId = repository.mainUserId
             if (targetUserId == UserHandle.USER_NULL) {
                 // When a target user is not specified switch to last non guest user:
                 val lastSelectedNonGuestUserHandle = repository.lastSelectedNonGuestUserId
-                if (lastSelectedNonGuestUserHandle != UserHandle.USER_SYSTEM) {
+                if (lastSelectedNonGuestUserHandle != repository.mainUserId) {
                     val info =
                         withContext(backgroundDispatcher) {
                             manager.getUserInfo(lastSelectedNonGuestUserHandle)
@@ -215,8 +215,11 @@ constructor(
             // Create a new guest in the foreground, and then immediately switch to it
             val newGuestId = create(showDialog, dismissDialog)
             if (newGuestId == UserHandle.USER_NULL) {
-                Log.e(TAG, "Could not create new guest, switching back to system user")
-                switchUser(UserHandle.USER_SYSTEM)
+                Log.e(TAG, "Could not create new guest, switching back to main user")
+                val mainUser = withContext(backgroundDispatcher) { manager.mainUser?.identifier }
+
+                mainUser?.let { switchUser(it) }
+
                 withContext(backgroundDispatcher) {
                     manager.removeUserWhenPossible(
                         UserHandle.of(currentUser.id),
diff --git a/packages/SystemUI/tests/src/com/android/systemui/user/data/repository/UserRepositoryImplTest.kt b/packages/SystemUI/tests/src/com/android/systemui/user/data/repository/UserRepositoryImplTest.kt
index ccf378a71abd0..9312643a14537 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/user/data/repository/UserRepositoryImplTest.kt
+++ b/packages/SystemUI/tests/src/com/android/systemui/user/data/repository/UserRepositoryImplTest.kt
@@ -128,6 +128,11 @@ class UserRepositoryImplTest : SysuiTestCase() {
 
     @Test
     fun refreshUsers() = runSelfCancelingTest {
+        val mainUserId = 10
+        val mainUser = mock(UserHandle::class.java)
+        whenever(manager.mainUser).thenReturn(mainUser)
+        whenever(mainUser.identifier).thenReturn(mainUserId)
+
         underTest = create(this)
         val initialExpectedValue =
             setUpUsers(
@@ -166,6 +171,7 @@ class UserRepositoryImplTest : SysuiTestCase() {
         assertThat(selectedUserInfo).isEqualTo(thirdExpectedValue[1])
         assertThat(selectedUserInfo?.isGuest).isTrue()
         assertThat(underTest.lastSelectedNonGuestUserId).isEqualTo(selectedNonGuestUserId)
+        assertThat(underTest.mainUserId).isEqualTo(mainUserId)
     }
 
     @Test
diff --git a/packages/SystemUI/tests/src/com/android/systemui/user/domain/interactor/GuestUserInteractorTest.kt b/packages/SystemUI/tests/src/com/android/systemui/user/domain/interactor/GuestUserInteractorTest.kt
index fb781e850b09b..cc23485f4a610 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/user/domain/interactor/GuestUserInteractorTest.kt
+++ b/packages/SystemUI/tests/src/com/android/systemui/user/domain/interactor/GuestUserInteractorTest.kt
@@ -204,10 +204,12 @@ class GuestUserInteractorTest : SysuiTestCase() {
         }
 
     @Test
-    fun `exit - last non-guest was removed - returns to system`() =
+    fun `exit - last non-guest was removed - returns to main user`() =
         runBlocking(IMMEDIATE) {
             val removedUserId = 310
+            val mainUserId = 10
             repository.lastSelectedNonGuestUserId = removedUserId
+            repository.mainUserId = mainUserId
             repository.setSelectedUserInfo(GUEST_USER_INFO)
 
             underTest.exit(
@@ -221,7 +223,7 @@ class GuestUserInteractorTest : SysuiTestCase() {
 
             verify(manager, never()).markGuestForDeletion(anyInt())
             verify(manager, never()).removeUser(anyInt())
-            verify(switchUser).invoke(UserHandle.USER_SYSTEM)
+            verify(switchUser).invoke(mainUserId)
         }
 
     @Test
diff --git a/packages/SystemUI/tests/utils/src/com/android/systemui/user/data/repository/FakeUserRepository.kt b/packages/SystemUI/tests/utils/src/com/android/systemui/user/data/repository/FakeUserRepository.kt
index 1a8e244bf54f1..53bb340fc167f 100644
--- a/packages/SystemUI/tests/utils/src/com/android/systemui/user/data/repository/FakeUserRepository.kt
+++ b/packages/SystemUI/tests/utils/src/com/android/systemui/user/data/repository/FakeUserRepository.kt
@@ -28,6 +28,10 @@ import kotlinx.coroutines.flow.filterNotNull
 import kotlinx.coroutines.yield
 
 class FakeUserRepository : UserRepository {
+    companion object {
+        // User id to represent a non system (human) user id. We presume this is the main user.
+        private const val MAIN_USER_ID = 10
+    }
 
     private val _userSwitcherSettings = MutableStateFlow(UserSwitcherSettingsModel())
     override val userSwitcherSettings: Flow<UserSwitcherSettingsModel> =
@@ -43,7 +47,8 @@ class FakeUserRepository : UserRepository {
     override val userSwitchingInProgress: Flow<Boolean>
         get() = _userSwitchingInProgress
 
-    override var lastSelectedNonGuestUserId: Int = UserHandle.USER_SYSTEM
+    override var mainUserId: Int = MAIN_USER_ID
+    override var lastSelectedNonGuestUserId: Int = mainUserId
 
     private var _isGuestUserAutoCreated: Boolean = false
     override val isGuestUserAutoCreated: Boolean