diff --git a/core/modules/migrate_drupal_ui/src/Batch/MigrateUpgradeImportBatch.php b/core/modules/migrate_drupal_ui/src/Batch/MigrateUpgradeImportBatch.php
index 8d9fd8f..5d60960 100644
--- a/core/modules/migrate_drupal_ui/src/Batch/MigrateUpgradeImportBatch.php
+++ b/core/modules/migrate_drupal_ui/src/Batch/MigrateUpgradeImportBatch.php
@@ -105,6 +105,7 @@ public static function run($initial_ids, $config, &$context) {
     if ($definition['destination']['plugin'] === 'entity:file') {
       // Make sure we have a single trailing slash.
       $configuration['source']['constants']['source_base_path'] = rtrim($config['source_base_path'], '/') . '/';
+      $configuration['source']['constants']['source_private_file_path'] = rtrim($config['source_private_file_path'], '/') . '/';
     }
 
     /** @var \Drupal\migrate\Plugin\Migration $migration */
diff --git a/core/modules/migrate_drupal_ui/src/Form/MigrateUpgradeForm.php b/core/modules/migrate_drupal_ui/src/Form/MigrateUpgradeForm.php
index 90b0b61..2062b61 100644
--- a/core/modules/migrate_drupal_ui/src/Form/MigrateUpgradeForm.php
+++ b/core/modules/migrate_drupal_ui/src/Form/MigrateUpgradeForm.php
@@ -854,6 +854,15 @@ public function buildCredentialForm(array $form, FormStateInterface $form_state)
 
     $default_options = [];
 
+
+    $form['version'] = [
+      '#type' => 'radios',
+      '#default_value' => 6,
+      '#title' => $this->t('Drupal version of the source site'),
+      '#options' => [6 => t('Drupal 6'), 7 => t('Drupal 7')],
+      '#required' => TRUE,
+    ];
+
     $form['database'] = [
       '#type' => 'details',
       '#title' => $this->t('Source database'),
@@ -913,6 +922,21 @@ public function buildCredentialForm(array $form, FormStateInterface $form_state)
       '#description' => $this->t('To import files from your current Drupal site, enter a local file directory containing your site (e.g. /var/www/docroot), or your site address (for example http://example.com).'),
     ];
 
+    $form['source']['source_private_file_path'] = [
+      '#type' => 'textfield',
+      '#title' => $this->t('Private file directory'),
+      '#default_value' => '',
+      '#description' => $this->t('To import private files from your current Drupal site, enter a local file directory containing your site (e.g. /var/www/docroot), or your site address (for example http://example.com).'),
+      '#states' => [
+        'invisible' => [
+          ':input[name="version"]' => ['value' => 6],
+        ],
+        'visible' => [
+          ':input[name="version"]' => ['value' => 7],
+        ],
+      ],
+    ];
+
     $form['actions'] = ['#type' => 'actions'];
     $form['actions']['save'] = [
       '#type' => 'submit',
@@ -961,6 +985,12 @@ public function validateCredentialForm(array &$form, FormStateInterface $form_st
       if (!$version) {
         $form_state->setErrorByName($database['driver'] . '][0', $this->t('Source database does not contain a recognizable Drupal version.'));
       }
+      elseif ($version != $form_state->getValue('version')) {
+        $form_state->setErrorByName($database['driver'] . '][0', $this->t('Source database is Drupal version @version but version @selected was selected.', [
+          '@version' => $version,
+          '@selected' => $form_state->getValue('version'),
+        ]));
+      }
       else {
         $this->createDatabaseStateSettings($database, $version);
         $migrations = $this->getMigrations('migrate_drupal_' . $version, $version);
@@ -978,6 +1008,7 @@ public function validateCredentialForm(array &$form, FormStateInterface $form_st
         // Store the retrieved migration IDs in form storage.
         $form_state->set('migrations', $migration_array);
         $form_state->set('source_base_path', $form_state->getValue('source_base_path'));
+        $form_state->set('source_private_file_path', $form_state->getValue('source_private_file_path'));
 
         // Store the retrived system data in form storage.
         $form_state->set('system_data', $system_data);
@@ -1126,6 +1157,7 @@ public function submitConfirmForm(array &$form, FormStateInterface $form_state)
 
     $migrations = $storage['migrations'];
     $config['source_base_path'] = $storage['source_base_path'];
+    $config['source_private_file_path'] = $storage['source_private_file_path'];
     $batch = [
       'title' => $this->t('Running upgrade'),
       'progress_message' => '',
diff --git a/core/modules/migrate_drupal_ui/src/Tests/MigrateUpgradeTestBase.php b/core/modules/migrate_drupal_ui/src/Tests/MigrateUpgradeTestBase.php
index c139291..b0a9cc9 100644
--- a/core/modules/migrate_drupal_ui/src/Tests/MigrateUpgradeTestBase.php
+++ b/core/modules/migrate_drupal_ui/src/Tests/MigrateUpgradeTestBase.php
@@ -121,6 +121,8 @@ protected function testMigrateUpgrade() {
     $edit = [
       $driver => $connection_options,
       'source_base_path' => $this->getSourceBasePath(),
+      'source_private_file_path' => $this->getSourcePrivateFilePath(),
+      'version' => $this->getSourceDrupalVersion(),
     ];
     if (count($drivers) !== 1) {
       $edit['driver'] = $driver;
@@ -186,6 +188,22 @@ protected function testMigrateUpgrade() {
   abstract protected function getSourceBasePath();
 
   /**
+   * Gets the source base path for the concrete test.
+   *
+   * @return string
+   *   The source base path.
+   */
+  abstract protected function getSourcePrivateFilePath();
+
+  /**
+   * Gets the source base path for the concrete test.
+   *
+   * @return string
+   *   The source base path.
+   */
+  abstract protected function getSourceDrupalVersion();
+
+  /**
    * Gets the expected number of entities per entity type after migration.
    *
    * @return int[]
diff --git a/core/modules/migrate_drupal_ui/src/Tests/d6/MigrateUpgrade6Test.php b/core/modules/migrate_drupal_ui/src/Tests/d6/MigrateUpgrade6Test.php
index 50829f0..b446bcb 100644
--- a/core/modules/migrate_drupal_ui/src/Tests/d6/MigrateUpgrade6Test.php
+++ b/core/modules/migrate_drupal_ui/src/Tests/d6/MigrateUpgrade6Test.php
@@ -32,6 +32,20 @@ protected function getSourceBasePath() {
   /**
    * {@inheritdoc}
    */
+  protected function getSourcePrivateFilePath() {
+    return '';
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getSourceDrupalVersion() {
+    return 6;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
   protected function getEntityCounts() {
     return [
       'block' => 30,
diff --git a/core/modules/migrate_drupal_ui/src/Tests/d7/MigrateUpgrade7Test.php b/core/modules/migrate_drupal_ui/src/Tests/d7/MigrateUpgrade7Test.php
index 77bc2ab..657ac17 100644
--- a/core/modules/migrate_drupal_ui/src/Tests/d7/MigrateUpgrade7Test.php
+++ b/core/modules/migrate_drupal_ui/src/Tests/d7/MigrateUpgrade7Test.php
@@ -32,6 +32,20 @@ protected function getSourceBasePath() {
   /**
    * {@inheritdoc}
    */
+  protected function getSourcePrivateFilePath() {
+    return __DIR__ . '/files';
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getSourceDrupalVersion() {
+    return 7;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
   protected function getEntityCounts() {
     return [
       'block' => 25,