diff --git a/core/modules/user/src/Entity/User.php b/core/modules/user/src/Entity/User.php
index aefa2a43c6..f7859eeddb 100644
--- a/core/modules/user/src/Entity/User.php
+++ b/core/modules/user/src/Entity/User.php
@@ -108,14 +108,6 @@ public function preSave(EntityStorageInterface $storage) {
         \Drupal::service('user.data')->set('user', $this->id(), substr($key, 5), $this->{$key});
       }
     }
-
-    // Set the default timezone if necessary.
-    if (!$this->getTimeZone()) {
-      $config = \Drupal::config('system.date');
-      if ($config->get('timezone.user.configurable') && $config->get('timezone.user.default') == UserInterface::TIMEZONE_DEFAULT) {
-        $this->set('timezone', $config->get('timezone.default'));
-      }
-    }
   }
 
   /**
@@ -525,6 +517,11 @@ public static function baseFieldDefinitions(EntityTypeInterface $entity_type) {
       ]);
     $fields['timezone']->getItemDefinition()->setClass(TimeZoneItem::class);
 
+    $config = \Drupal::config('system.date');
+    if ($config->get('timezone.user.configurable') && $config->get('timezone.user.default') == UserInterface::TIMEZONE_DEFAULT) {
+      $fields['timezone']->setDefaultValue($config->get('timezone.default'));
+    }
+
     $fields['status'] = BaseFieldDefinition::create('boolean')
       ->setLabel(t('User status'))
       ->setDescription(t('Whether the user is active or blocked.'))
diff --git a/core/modules/user/tests/src/Kernel/Migrate/d6/MigrateUserTest.php b/core/modules/user/tests/src/Kernel/Migrate/d6/MigrateUserTest.php
index 558d3d01f8..1024071a27 100644
--- a/core/modules/user/tests/src/Kernel/Migrate/d6/MigrateUserTest.php
+++ b/core/modules/user/tests/src/Kernel/Migrate/d6/MigrateUserTest.php
@@ -106,7 +106,7 @@ public function testUser() {
       $is_blocked = $source->status == 0;
       $this->assertSame($is_blocked, $user->isBlocked());
       $expected_timezone_name = $source->timezone_name ?: $this->config('system.date')->get('timezone.default');
-      $this->assertSame($expected_timezone_name, $user->getTimeZone());
+      $this->assertEquals($expected_timezone_name, $user->getTimeZone());
       $this->assertSame($source->init, $user->getInitialEmail());
       $this->assertSame($roles, $user->getRoles());