diff --git a/core/lib/Drupal/Core/Entity/Sql/DefaultTableMapping.php b/core/lib/Drupal/Core/Entity/Sql/DefaultTableMapping.php
index 78e6c06..d6ca5db 100644
--- a/core/lib/Drupal/Core/Entity/Sql/DefaultTableMapping.php
+++ b/core/lib/Drupal/Core/Entity/Sql/DefaultTableMapping.php
@@ -247,8 +247,8 @@ public static function create(ContentEntityTypeInterface $entity_type, array $st
   /**
    * Gets the base table name.
    *
-   * @return string|null
-   *   The table name.
+   * @return string
+   *   The base table name.
    *
    * @internal
    */
diff --git a/core/tests/Drupal/Tests/Core/Entity/Sql/SqlContentEntityStorageTest.php b/core/tests/Drupal/Tests/Core/Entity/Sql/SqlContentEntityStorageTest.php
index d8ab13c..376b556 100644
--- a/core/tests/Drupal/Tests/Core/Entity/Sql/SqlContentEntityStorageTest.php
+++ b/core/tests/Drupal/Tests/Core/Entity/Sql/SqlContentEntityStorageTest.php
@@ -15,6 +15,7 @@
 use Drupal\Core\Entity\EntityStorageInterface;
 use Drupal\Core\Entity\EntityTypeManagerInterface;
 use Drupal\Core\Entity\Query\QueryFactoryInterface;
+use Drupal\Core\Entity\Sql\DefaultTableMapping;
 use Drupal\Core\Entity\Sql\SqlContentEntityStorage;
 use Drupal\Core\Language\Language;
 use Drupal\Tests\UnitTestCase;
@@ -313,6 +314,51 @@ public function providerTestGetRevisionDataTable() {
   }
 
   /**
+   * Tests that setting a new table mapping also updates the table names.
+   *
+   * @covers ::setTableMapping
+   */
+  public function testSetTableMapping() {
+    $this->entityType->expects($this->any())
+      ->method('isRevisionable')
+      ->will($this->returnValue(FALSE));
+    $this->entityType->expects($this->any())
+      ->method('isTranslatable')
+      ->will($this->returnValue(FALSE));
+    $this->entityType->expects($this->any())
+      ->method('getRevisionMetadataKeys')
+      ->willReturn([]);
+
+    $this->setUpEntityStorage();
+
+    $this->assertSame('entity_test', $this->entityStorage->getBaseTable());
+    $this->assertNull($this->entityStorage->getRevisionTable());
+    $this->assertNull($this->entityStorage->getDataTable());
+    $this->assertNull($this->entityStorage->getRevisionDataTable());
+
+    // Change the entity type definition and instantiate a new table mapping
+    // with it.
+    $updated_entity_type = $this->createMock('Drupal\Core\Entity\ContentEntityTypeInterface');
+    $updated_entity_type->expects($this->any())
+      ->method('id')
+      ->will($this->returnValue($this->entityTypeId));
+    $updated_entity_type->expects($this->any())
+      ->method('isRevisionable')
+      ->will($this->returnValue(TRUE));
+    $updated_entity_type->expects($this->any())
+      ->method('isTranslatable')
+      ->will($this->returnValue(TRUE));
+
+    $table_mapping = new DefaultTableMapping($updated_entity_type, []);
+    $this->entityStorage->setTableMapping($table_mapping);
+
+    $this->assertSame('entity_test', $this->entityStorage->getBaseTable());
+    $this->assertSame('entity_test_revision', $this->entityStorage->getRevisionTable());
+    $this->assertSame('entity_test_field_data', $this->entityStorage->getDataTable());
+    $this->assertSame('entity_test_field_revision', $this->entityStorage->getRevisionDataTable());
+  }
+
+  /**
    * Tests ContentEntityDatabaseStorage::onEntityTypeCreate().
    *
    * @covers ::__construct