diff --git a/core/modules/migrate_drupal/tests/fixtures/drupal6.php b/core/modules/migrate_drupal/tests/fixtures/drupal6.php
index 9debae0..b18a4b3 100644
--- a/core/modules/migrate_drupal/tests/fixtures/drupal6.php
+++ b/core/modules/migrate_drupal/tests/fixtures/drupal6.php
@@ -41378,6 +41378,40 @@
   'tnid' => '10',
   'translate' => '0',
 ))
+->values(array(
+  'nid' => '12',
+  'vid' => '15',
+  'type' => 'page',
+  'language' => 'zu',
+  'title' => 'Abantu zulu',
+  'uid' => '1',
+  'status' => '1',
+  'created' => '1444238800',
+  'changed' => '1444238808',
+  'comment' => '0',
+  'promote' => '0',
+  'moderate' => '0',
+  'sticky' => '0',
+  'tnid' => '12',
+  'translate' => '0',
+))
+->values(array(
+  'nid' => '13',
+  'vid' => '16',
+  'type' => 'page',
+  'language' => 'en',
+  'title' => 'The Zulu People',
+  'uid' => '1',
+  'status' => '1',
+  'created' => '1444239050',
+  'changed' => '1444239050',
+  'comment' => '0',
+  'promote' => '0',
+  'moderate' => '0',
+  'sticky' => '0',
+  'tnid' => '12',
+  'translate' => '0',
+))
 ->execute();
 
 $connection->schema()->createTable('node_access', array(
@@ -41807,6 +41841,28 @@
   'timestamp' => '1444239050',
   'format' => '1',
 ))
+->values(array(
+  'nid' => '12',
+  'vid' => '15',
+  'uid' => '1',
+  'title' => 'Abantu zulu',
+  'body' => "Mr. Crusher, ready a collision course with the Borg ship.",
+  'teaser' => "Mr. Crusher, ready a collision course with the Borg ship.",
+  'log' => '',
+  'timestamp' => '1444238808',
+  'format' => '1',
+))
+->values(array(
+  'nid' => '13',
+  'vid' => '16',
+  'uid' => '1',
+  'title' => 'The Zulu People',
+  'body' => 'Mr. Crusher, ready a collision course with the Borg ship.',
+  'teaser' => 'Mr. Crusher, ready a collision course with the Borg ship.',
+  'log' => '',
+  'timestamp' => '1444239050',
+  'format' => '1',
+))
 ->execute();
 
 $connection->schema()->createTable('node_type', array(
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 3b53992..50829f0 100644
--- a/core/modules/migrate_drupal_ui/src/Tests/d6/MigrateUpgrade6Test.php
+++ b/core/modules/migrate_drupal_ui/src/Tests/d6/MigrateUpgrade6Test.php
@@ -49,7 +49,7 @@ protected function getEntityCounts() {
       'image_style' => 5,
       'language_content_settings' => 2,
       'migration' => 105,
-      'node' => 10,
+      'node' => 11,
       'node_type' => 11,
       'rdf_mapping' => 5,
       'search_page' => 2,
diff --git a/core/modules/node/migration_templates/d6_node_translation.yml b/core/modules/node/migration_templates/d6_node_translation.yml
index 07440ab..3b923d1 100644
--- a/core/modules/node/migration_templates/d6_node_translation.yml
+++ b/core/modules/node/migration_templates/d6_node_translation.yml
@@ -31,6 +31,7 @@ process:
   revision_uid: revision_uid
   revision_log: log
   revision_timestamp: timestamp
+  content_translation_source: source_langcode
 
 #  unmapped d6 fields.
 #  translate
diff --git a/core/modules/node/src/Plugin/migrate/source/d6/Node.php b/core/modules/node/src/Plugin/migrate/source/d6/Node.php
index 8686415..20ee31b 100644
--- a/core/modules/node/src/Plugin/migrate/source/d6/Node.php
+++ b/core/modules/node/src/Plugin/migrate/source/d6/Node.php
@@ -68,6 +68,13 @@ public function query() {
     $query->addField('n', 'uid', 'node_uid');
     $query->addField('nr', 'uid', 'revision_uid');
 
+    // If the content_translation module is enabled, get the source langcode
+    // to fill the content_translation_source field.
+    if ($this->moduleExists('content_translation')) {
+      $query->leftJoin('node', 'nt', 'n.tnid = nt.nid');
+      $query->addField('nt', 'language', 'source_langcode');
+    }
+
     if (isset($this->configuration['node_type'])) {
       $query->condition('n.type', $this->configuration['node_type']);
     }
diff --git a/core/modules/node/tests/src/Kernel/Migrate/d6/MigrateNodeTest.php b/core/modules/node/tests/src/Kernel/Migrate/d6/MigrateNodeTest.php
index 122199f..7a0a272 100644
--- a/core/modules/node/tests/src/Kernel/Migrate/d6/MigrateNodeTest.php
+++ b/core/modules/node/tests/src/Kernel/Migrate/d6/MigrateNodeTest.php
@@ -28,7 +28,12 @@ protected function setUp() {
     parent::setUp();
     $this->setUpMigratedFiles();
     $this->installSchema('file', ['file_usage']);
-    $this->executeMigrations(['language', 'd6_node', 'd6_node_translation']);
+    $this->executeMigrations([
+      'language',
+      'd6_language_content_settings',
+      'd6_node',
+      'd6_node_translation',
+    ]);
   }
 
   /**
@@ -96,6 +101,14 @@ public function testNode() {
     $this->assertIdentical('The Real McCoy', $node->title->value);
     $this->assertTrue($node->hasTranslation('fr'), "Node 10 has french translation");
 
+    // Test that content_translation_source is set.
+    $manager = $this->container->get('content_translation.manager');
+    $this->assertIdentical('en', $manager->getTranslationMetadata($node->getTranslation('fr'))->getSource());
+
+    // Test that content_translation_source for a source other than English.
+    $node = Node::load(12);
+    $this->assertIdentical('zu', $manager->getTranslationMetadata($node->getTranslation('en'))->getSource());
+
     // Node 11 is a translation of node 10, and should not be imported separately.
     $this->assertNull(Node::load(11), "Node 11 doesn't exist in D8, it was a translation");