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 6b1fc1b..9ca8a16 100644
--- a/core/modules/migrate_drupal_ui/src/Form/MigrateUpgradeForm.php
+++ b/core/modules/migrate_drupal_ui/src/Form/MigrateUpgradeForm.php
@@ -426,7 +426,7 @@ class MigrateUpgradeForm extends ConfirmFormBase {
       'source_module' => 'simpletest',
       'destination_module' => 'simpletest',
     ],
-    'd6_statistics_settings' => [
+    'statistics_settings' => [
       'source_module' => 'statistics',
       'destination_module' => 'statistics',
     ],
@@ -862,6 +862,15 @@ public function buildCredentialForm(array $form, FormStateInterface $form_state)
 
     $default_options = [];
 
+
+    $form['version'] = [
+      '#type' => 'radios',
+      '#default_value' => 7,
+      '#title' => $this->t('Drupal version of the source site'),
+      '#options' => [6 => $this->t('Drupal 6'), 7 => $this->t('Drupal 7')],
+      '#required' => TRUE,
+    ];
+
     $form['database'] = [
       '#type' => 'details',
       '#title' => $this->t('Source database'),
@@ -915,10 +924,47 @@ public function buildCredentialForm(array $form, FormStateInterface $form_state)
       '#title' => $this->t('Source files'),
       '#open' => TRUE,
     ];
-    $form['source']['source_base_path'] = [
+    $form['source']['d6_source_base_path'] = [
       '#type' => 'textfield',
       '#title' => $this->t('Files directory'),
       '#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).'),
+      '#states' => [
+        'invisible' => [
+          ':input[name="version"]' => ['value' => 7],
+        ],
+        'visible' => [
+          ':input[name="version"]' => ['value' => 6],
+        ],
+      ],
+    ];
+
+    $form['source']['source_base_path'] = [
+      '#type' => 'textfield',
+      '#title' => $this->t('Public files directory'),
+      '#description' => $this->t('To import public 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['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).'),
+      '#states' => [
+        'invisible' => [
+          ':input[name="version"]' => ['value' => 6],
+        ],
+        'visible' => [
+          ':input[name="version"]' => ['value' => 7],
+        ],
+      ],
     ];
 
     $form['actions'] = ['#type' => 'actions'];
@@ -969,6 +1015,12 @@ public function validateCredentialForm(array &$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, $version);
@@ -985,7 +1037,10 @@ public function validateCredentialForm(array &$form, FormStateInterface $form_st
 
         // Store the retrieved migration IDs in form storage.
         $form_state->set('migrations', $migration_array);
+        $form_state->set('version', $form_state->getValue('version'));
+        $form_state->set('d6_source_base_path', $form_state->getValue('d6_source_base_path'));
         $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', $system_data);
@@ -1133,7 +1188,13 @@ public function submitConfirmForm(array &$form, FormStateInterface $form_state)
     $storage = $form_state->getStorage();
 
     $migrations = $storage['migrations'];
-    $config['source_base_path'] = $storage['source_base_path'];
+    if ($storage['version'] == '6') {
+      $config['source_base_path'] = $storage['d6_source_base_path'];
+    }
+    else {
+      $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 85a9e79..49452af 100644
--- a/core/modules/migrate_drupal_ui/src/Tests/MigrateUpgradeTestBase.php
+++ b/core/modules/migrate_drupal_ui/src/Tests/MigrateUpgradeTestBase.php
@@ -118,10 +118,15 @@ public function testMigrateUpgrade() {
     $drivers = drupal_get_database_types();
     $form = $drivers[$driver]->getFormOptions($connection_options);
     $connection_options = array_intersect_key($connection_options, $form + $form['advanced_options']);
+    $version = $this->getSourceDrupalVersion();
     $edit = [
       $driver => $connection_options,
-      'source_base_path' => $this->getSourceBasePath(),
+      'source_private_file_path' => $this->getSourcePrivateFilePath(),
+      'version' => $version,
     ];
+    if ($version == 6) {
+      $edit['d6_source_base_path'] = $this->getSourceBasePath();
+    }
     if (count($drivers) !== 1) {
       $edit['driver'] = $driver;
     }
@@ -187,6 +192,22 @@ public 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 404f21b..7b0c846 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 86f1ca9..54b299f 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,