diff -u b/core/modules/migrate/src/Plugin/migrate/destination/EntityConfigBase.php b/core/modules/migrate/src/Plugin/migrate/destination/EntityConfigBase.php
--- b/core/modules/migrate/src/Plugin/migrate/destination/EntityConfigBase.php
+++ b/core/modules/migrate/src/Plugin/migrate/destination/EntityConfigBase.php
@@ -249,7 +249,8 @@
       $config_override->delete();
     }
     else {
-      parent::rollback($destination_identifier);
+      $destination_identifier = implode('.', $destination_identifier);
+      parent::rollback(array($destination_identifier));
     }
   }
 
reverted:
--- b/core/modules/migrate/tests/src/Kernel/MigrateEntityConfigRollbackTest.php
+++ /dev/null
@@ -1,171 +0,0 @@
-<?php
-
-namespace Drupal\Tests\migrate\Kernel;
-
-use Drupal\migrate\MigrateExecutable;
-use Drupal\migrate\Plugin\MigrateIdMapInterface;
-use Drupal\migrate\Row;
-use Drupal\taxonomy\Entity\Term;
-use Drupal\taxonomy\Entity\Vocabulary;
-
-/**
- * Tests rolling back of imports.
- *
- * @group migrate
- */
-class MigrateRollbackEntityConfigTest extends MigrateTestBase {
-
-  /**
-   * Modules to enable.
-   *
-   * @var array
-   */
-  public static $modules = ['field', 'taxonomy', 'text', 'language', 'config_translation'];
-
-  /**
-   * {@inheritdoc}
-   */
-  protected function setUp() {
-    parent::setUp();
-    $this->installEntitySchema('taxonomy_vocabulary');
-    $this->installEntitySchema('taxonomy_term');
-    $this->installConfig(['taxonomy']);
-  }
-
-  /**
-   * Tests rolling back configuration entity translations.
-   */
-  public function testConfigEntityRollback() {
-    // We use vocabularies to demonstrate importing and rolling back
-    // configuration entities with translations. First, import vocabularies.
-    $vocabulary_data_rows = [
-      ['id' => '1', 'name' => 'categories', 'weight' => '2'],
-      ['id' => '2', 'name' => 'tags', 'weight' => '1'],
-    ];
-    $ids = ['id' => ['type' => 'integer']];
-    $definition = [
-      'id' => 'vocabularies',
-      'migration_tags' => ['Import and rollback test'],
-      'source' => [
-        'plugin' => 'embedded_data',
-        'data_rows' => $vocabulary_data_rows,
-        'ids' => $ids,
-      ],
-      'process' => [
-        'vid' => 'id',
-        'name' => 'name',
-        'weight' => 'weight',
-      ],
-      'destination' => ['plugin' => 'entity:taxonomy_vocabulary'],
-    ];
-
-    /** @var \Drupal\migrate\Plugin\Migration $vocabulary_migration */
-    $vocabulary_migration = \Drupal::service('plugin.manager.migration')
-      ->createStubMigration($definition);
-    $vocabulary_id_map = $vocabulary_migration->getIdMap();
-
-    $this->assertTrue($vocabulary_migration->getDestinationPlugin()
-      ->supportsRollback());
-
-    // Import and validate vocabulary config entities were created.
-    $vocabulary_executable = new MigrateExecutable($vocabulary_migration, $this);
-    $vocabulary_executable->import();
-    foreach ($vocabulary_data_rows as $row) {
-      /** @var Vocabulary $vocabulary */
-      $vocabulary = Vocabulary::load($row['id']);
-      $this->assertTrue($vocabulary);
-      $map_row = $vocabulary_id_map->getRowBySource(['id' => $row['id']]);
-      $this->assertNotNull($map_row['destid1']);
-    }
-
-    // Second, import translations of the vocabulary name property.
-    $vocabulary_i18n_data_rows = [
-      [
-        'id' => '1',
-        'name' => '1',
-        'language' => 'fr',
-        'property' => 'name',
-        'translation' => 'fr - categories'
-      ],
-      [
-        'id' => '2',
-        'name' => '2',
-        'language' => 'fr',
-        'property' => 'name',
-        'translation' => 'fr - tags'
-      ],
-    ];
-    $ids = [
-      'id' => ['type' => 'integer'],
-      'language' => ['type' => 'string'],
-    ];
-    $definition = [
-      'id' => 'i18n_vocabularies',
-      'migration_tags' => ['Import and rollback test'],
-      'source' => [
-        'plugin' => 'embedded_data',
-        'data_rows' => $vocabulary_i18n_data_rows,
-        'ids' => $ids,
-        'constants' => [
-          'name' => 'name',
-        ]
-      ],
-      'process' => [
-        'vid' => 'id',
-        'langcode' => 'language',
-        'property' => 'constants/name',
-        'translation' => 'translation',
-      ],
-      'destination' => [
-        'plugin' => 'entity:taxonomy_vocabulary',
-        'translations' => 'true',
-      ],
-    ];
-
-    $vocabulary_i18n__migration = \Drupal::service('plugin.manager.migration')
-      ->createStubMigration($definition);
-    $vocabulary_i18n_id_map = $vocabulary_i18n__migration->getIdMap();
-
-    $this->assertTrue($vocabulary_i18n__migration->getDestinationPlugin()
-      ->supportsRollback());
-
-    // Import and validate vocabulary config entities were created.
-    $vocabulary_i18n_executable = new MigrateExecutable($vocabulary_i18n__migration, $this);
-    $vocabulary_i18n_executable->import();
-
-    $language_manager = \Drupal::service('language_manager');
-    foreach ($vocabulary_i18n_data_rows as $row) {
-      $langcode = $row['language'];
-      $id = 'taxonomy.vocabulary.' . $row['id'];
-      /** @var \Drupal\language\Config\LanguageConfigOverride $config_translation */
-      $config_translation = $language_manager->getLanguageConfigOverride($langcode, $id);
-      $this->assertSame($row['translation'], $config_translation->get('name'));
-      $map_row = $vocabulary_i18n_id_map->getRowBySource(['id' => $row['id'], 'language' => $row['language']]);
-      $this->assertNotNull($map_row['destid1']);
-    }
-
-    // Perform the rollback and confirm the translation was deleted and the map
-    // table row removed.
-    $vocabulary_i18n_executable->rollback();
-    foreach ($vocabulary_i18n_data_rows as $row) {
-      $langcode = $row['language'];
-      $id = 'taxonomy.vocabulary.' . $row['id'];
-      /** @var \Drupal\language\Config\LanguageConfigOverride $config_translation */
-      $config_translation = $language_manager->getLanguageConfigOverride($langcode, $id);
-      $this->assertNull($config_translation->get('name'));
-      $map_row = $vocabulary_i18n_id_map->getRowBySource(['id' => $row['id'], 'language' => $row['language']]);
-      $this->assertFalse($map_row);
-    }
-
-    // Conform the Original vocabulary still exists.
-    foreach ($vocabulary_data_rows as $row) {
-      /** @var Vocabulary $vocabulary */
-      $vocabulary = Vocabulary::load($row['id']);
-      $this->assertTrue($vocabulary);
-      $map_row = $vocabulary_id_map->getRowBySource(['id' => $row['id']]);
-      $this->assertNotNull($map_row['destid1']);
-    }
-
-  }
-
-}
only in patch2:
unchanged:
--- /dev/null
+++ b/core/modules/migrate/tests/src/Kernel/MigrateRollbackEntityConfigTest.php
@@ -0,0 +1,171 @@
+<?php
+
+namespace Drupal\Tests\migrate\Kernel;
+
+use Drupal\migrate\MigrateExecutable;
+use Drupal\migrate\Plugin\MigrateIdMapInterface;
+use Drupal\migrate\Row;
+use Drupal\taxonomy\Entity\Term;
+use Drupal\taxonomy\Entity\Vocabulary;
+
+/**
+ * Tests rolling back of imports.
+ *
+ * @group migrate
+ */
+class MigrateRollbackEntityConfigTest extends MigrateTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  public static $modules = ['field', 'taxonomy', 'text', 'language', 'config_translation'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+    $this->installEntitySchema('taxonomy_vocabulary');
+    $this->installEntitySchema('taxonomy_term');
+    $this->installConfig(['taxonomy']);
+  }
+
+  /**
+   * Tests rolling back configuration entity translations.
+   */
+  public function testConfigEntityRollback() {
+    // We use vocabularies to demonstrate importing and rolling back
+    // configuration entities with translations. First, import vocabularies.
+    $vocabulary_data_rows = [
+      ['id' => '1', 'name' => 'categories', 'weight' => '2'],
+      ['id' => '2', 'name' => 'tags', 'weight' => '1'],
+    ];
+    $ids = ['id' => ['type' => 'integer']];
+    $definition = [
+      'id' => 'vocabularies',
+      'migration_tags' => ['Import and rollback test'],
+      'source' => [
+        'plugin' => 'embedded_data',
+        'data_rows' => $vocabulary_data_rows,
+        'ids' => $ids,
+      ],
+      'process' => [
+        'vid' => 'id',
+        'name' => 'name',
+        'weight' => 'weight',
+      ],
+      'destination' => ['plugin' => 'entity:taxonomy_vocabulary'],
+    ];
+
+    /** @var \Drupal\migrate\Plugin\Migration $vocabulary_migration */
+    $vocabulary_migration = \Drupal::service('plugin.manager.migration')
+      ->createStubMigration($definition);
+    $vocabulary_id_map = $vocabulary_migration->getIdMap();
+
+    $this->assertTrue($vocabulary_migration->getDestinationPlugin()
+      ->supportsRollback());
+
+    // Import and validate vocabulary config entities were created.
+    $vocabulary_executable = new MigrateExecutable($vocabulary_migration, $this);
+    $vocabulary_executable->import();
+    foreach ($vocabulary_data_rows as $row) {
+      /** @var Vocabulary $vocabulary */
+      $vocabulary = Vocabulary::load($row['id']);
+      $this->assertTrue($vocabulary);
+      $map_row = $vocabulary_id_map->getRowBySource(['id' => $row['id']]);
+      $this->assertNotNull($map_row['destid1']);
+    }
+
+    // Second, import translations of the vocabulary name property.
+    $vocabulary_i18n_data_rows = [
+      [
+        'id' => '1',
+        'name' => '1',
+        'language' => 'fr',
+        'property' => 'name',
+        'translation' => 'fr - categories'
+      ],
+      [
+        'id' => '2',
+        'name' => '2',
+        'language' => 'fr',
+        'property' => 'name',
+        'translation' => 'fr - tags'
+      ],
+    ];
+    $ids = [
+      'id' => ['type' => 'integer'],
+      'language' => ['type' => 'string'],
+    ];
+    $definition = [
+      'id' => 'i18n_vocabularies',
+      'migration_tags' => ['Import and rollback test'],
+      'source' => [
+        'plugin' => 'embedded_data',
+        'data_rows' => $vocabulary_i18n_data_rows,
+        'ids' => $ids,
+        'constants' => [
+          'name' => 'name',
+        ]
+      ],
+      'process' => [
+        'vid' => 'id',
+        'langcode' => 'language',
+        'property' => 'constants/name',
+        'translation' => 'translation',
+      ],
+      'destination' => [
+        'plugin' => 'entity:taxonomy_vocabulary',
+        'translations' => 'true',
+      ],
+    ];
+
+    $vocabulary_i18n__migration = \Drupal::service('plugin.manager.migration')
+      ->createStubMigration($definition);
+    $vocabulary_i18n_id_map = $vocabulary_i18n__migration->getIdMap();
+
+    $this->assertTrue($vocabulary_i18n__migration->getDestinationPlugin()
+      ->supportsRollback());
+
+    // Import and validate vocabulary config entities were created.
+    $vocabulary_i18n_executable = new MigrateExecutable($vocabulary_i18n__migration, $this);
+    $vocabulary_i18n_executable->import();
+
+    $language_manager = \Drupal::service('language_manager');
+    foreach ($vocabulary_i18n_data_rows as $row) {
+      $langcode = $row['language'];
+      $id = 'taxonomy.vocabulary.' . $row['id'];
+      /** @var \Drupal\language\Config\LanguageConfigOverride $config_translation */
+      $config_translation = $language_manager->getLanguageConfigOverride($langcode, $id);
+      $this->assertSame($row['translation'], $config_translation->get('name'));
+      $map_row = $vocabulary_i18n_id_map->getRowBySource(['id' => $row['id'], 'language' => $row['language']]);
+      $this->assertNotNull($map_row['destid1']);
+    }
+
+    // Perform the rollback and confirm the translation was deleted and the map
+    // table row removed.
+    $vocabulary_i18n_executable->rollback();
+    foreach ($vocabulary_i18n_data_rows as $row) {
+      $langcode = $row['language'];
+      $id = 'taxonomy.vocabulary.' . $row['id'];
+      /** @var \Drupal\language\Config\LanguageConfigOverride $config_translation */
+      $config_translation = $language_manager->getLanguageConfigOverride($langcode, $id);
+      $this->assertNull($config_translation->get('name'));
+      $map_row = $vocabulary_i18n_id_map->getRowBySource(['id' => $row['id'], 'language' => $row['language']]);
+      $this->assertFalse($map_row);
+    }
+
+    // Conform the Original vocabulary still exists.
+    foreach ($vocabulary_data_rows as $row) {
+      /** @var Vocabulary $vocabulary */
+      $vocabulary = Vocabulary::load($row['id']);
+      $this->assertTrue($vocabulary);
+      $map_row = $vocabulary_id_map->getRowBySource(['id' => $row['id']]);
+      $this->assertNotNull($map_row['destid1']);
+    }
+
+  }
+
+}