diff --git a/core/modules/migrate/lib/Drupal/migrate/Plugin/migrate/process/MachineName.php b/core/modules/migrate/lib/Drupal/migrate/Plugin/migrate/process/MachineName.php
index 80532bc..3017590 100644
--- a/core/modules/migrate/lib/Drupal/migrate/Plugin/migrate/process/MachineName.php
+++ b/core/modules/migrate/lib/Drupal/migrate/Plugin/migrate/process/MachineName.php
@@ -11,6 +11,7 @@
 use Drupal\migrate\ProcessPluginBase;
 use Drupal\migrate\MigrateExecutable;
 use Drupal\migrate\Row;
+use Drupal\migrate\MigrateException;
 
 /**
  * This plugin creates a machine name.
@@ -37,7 +38,20 @@ public function transform($value, MigrateExecutable $migrate_executable, Row $ro
     $new_value = $this->getTransliteration()->transliterate($value, Language::LANGCODE_DEFAULT, '_');
     $new_value = strtolower($new_value);
     $new_value = preg_replace('/[^a-z0-9_]+/', '_', $new_value);
-    return preg_replace('/_+/', '_', $new_value);
+    $new_value = preg_replace('/_+/', '_', $new_value);
+    // Return a portion of the machine name, if an optional length is provided.
+    if (isset($this->configuration['length'])) {
+      $length = isset($this->configuration['length']) ? $this->configuration['length'] : NULL;
+      if (!is_null($length) && !is_int($length)) {
+        throw new MigrateException('Input substring length should be an integer.');
+      }
+      $start = isset($this->configuration['start']) ? $this->configuration['start'] : 0;
+      if (!is_int($start)) {
+        throw new MigrateException('Input substring start position should be an integer.');
+      }
+      $new_value = substr($new_value, $start, $length);
+    }
+    return $new_value;
   }
 
   /**
diff --git a/core/modules/migrate/tests/Drupal/migrate/Tests/process/MachineNameTest.php b/core/modules/migrate/tests/Drupal/migrate/Tests/process/MachineNameTest.php
index c1c41c6..1e6cefb 100644
--- a/core/modules/migrate/tests/Drupal/migrate/Tests/process/MachineNameTest.php
+++ b/core/modules/migrate/tests/Drupal/migrate/Tests/process/MachineNameTest.php
@@ -24,6 +24,16 @@ class MachineNameTest extends MigrateProcessTestCase {
   protected $transliteration;
 
   /**
+   * @var string $humanNameAscii
+   */
+  protected $humanNameAscii;
+
+  /**
+   * @var string $humanName
+   */
+  protected $humanName;
+
+  /**
    * {@inheritdoc}
    */
   public static function getInfo() {
@@ -47,34 +57,78 @@ protected function setUp() {
     $this->migrateExecutable = $this->getMockBuilder('Drupal\migrate\MigrateExecutable')
       ->disableOriginalConstructor()
       ->getMock();
+    $this->humanNameAscii = 'foo2, the.bar;2*&the%baz!YEE____HaW ';
+    $this->humanName = $this->humanNameAscii . 'áéő';
+    // Set transliteration to a mock object.
+    $this->transliteration
+      ->expects($this->any())
+      ->method('transliterate')
+      ->with($this->humanName)
+      ->will($this->returnValue($this->humanNameAscii . 'aeo'));
     parent::setUp();
   }
 
   /**
    * Tests machine name transformation of non-alphanumeric characters.
+   *
+   * The following transformations are performed:
+   *   - non-alphanumeric character (including spaces) -> underscore,
+   *   - Uppercase -> lowercase,
+   *   - Multiple consecutive underscore -> single underscore.
    */
   public function testMachineNames() {
-
-    // Tests the following transformations:
-    // - non-alphanumeric character (including spaces) -> underscore,
-    // - Uppercase -> lowercase,
-    // - Multiple consecutive underscore -> single underscore.
-    $human_name_ascii = 'foo2, the.bar;2*&the%baz!YEE____HaW ';
-    $human_name = $human_name_ascii .'áéő';
+    $plugin = new TestMachineName(array(), 'machine_name', array());
+    $plugin->setTransliteration($this->transliteration);
+    $value = $plugin->transform($this->humanName, $this->migrateExecutable, $this->row, 'destinationproperty');
     $expected_result = 'foo2_the_bar_2_the_baz_yee_haw_aeo';
-    // Test for calling transliterate on mock object.
-    $this->transliteration
-      ->expects($this->once())
-      ->method('transliterate')
-      ->with($human_name)
-      ->will($this->returnValue($human_name_ascii . 'aeo'));
+    $this->assertEquals($expected_result, $value);
+  }
 
-    $plugin = new TestMachineName(array(), 'machine_name', array());
+  /**
+   * Tests substring length and start options.
+   */
+  public function testMachineNameOptions() {
+    // Test using an optional substring length.
+    $configuration['length'] = -3;
+    $plugin = new TestMachineName($configuration, 'machine_name', array());
+    $plugin->setTransliteration($this->transliteration);
+    $value = $plugin->transform($this->humanName, $this->migrateExecutable, $this->row, 'destinationproperty');
+    $expected_result = 'foo2_the_bar_2_the_baz_yee_haw_';
+    $this->assertEquals($expected_result, $value);
+
+    // Test using an optional substring length and start position.
+    $configuration['start'] = 10;
+    $configuration['length'] = 15;
+    $plugin = new TestMachineName($configuration, 'machine_name', array());
     $plugin->setTransliteration($this->transliteration);
-    $value = $plugin->transform($human_name, $this->migrateExecutable, $this->row, 'destinationproperty');
+    $value = $plugin->transform($this->humanName, $this->migrateExecutable, $this->row, 'destinationproperty');
+    $expected_result = 'ar_2_the_baz_ye';
     $this->assertEquals($expected_result, $value);
   }
 
+  /**
+   * Tests that an invalid substring length option throws an exception.
+   */
+  public function testMachineNameOptionsInvalidLength() {
+    $this->setExpectedException('Drupal\migrate\MigrateException', 'Input substring length should be an integer.');
+    $configuration['length'] = 'foobar';
+    $plugin = new TestMachineName($configuration, 'machine_name', array());
+    $plugin->setTransliteration($this->transliteration);
+    $plugin->transform($this->humanName, $this->migrateExecutable, $this->row, 'destinationproperty');
+  }
+
+  /**
+   * Tests that an invalid substring start option throws an exception.
+   */
+  public function testMachineNameOptionsInvalidStart() {
+    $this->setExpectedException('Drupal\migrate\MigrateException', 'Input substring start position should be an integer.');
+    $configuration['start'] = 'foobar';
+    $configuration['length'] = 10;
+    $plugin = new TestMachineName($configuration, 'machine_name', array());
+    $plugin->setTransliteration($this->transliteration);
+    $plugin->transform($this->humanName, $this->migrateExecutable, $this->row, 'destinationproperty');
+  }
+
 }
 
 namespace Drupal\migrate\Plugin\migrate\process;