diff --git a/core/lib/Drupal/Core/Database/Driver/fake/FakeSelect.php b/core/lib/Drupal/Core/Database/Driver/fake/FakeSelect.php
index 9feb177..7e6a1e7 100644
--- a/core/lib/Drupal/Core/Database/Driver/fake/FakeSelect.php
+++ b/core/lib/Drupal/Core/Database/Driver/fake/FakeSelect.php
@@ -180,7 +180,7 @@ protected function executeJoins() {
     $fields = array();
     foreach ($this->fields as $field_info) {
       $this->fieldsWithTable[$field_info['table'] . '.' . $field_info['field']] = $field_info;
-      $fields[$field_info['table']][$field_info['field']] = NULL;
+      $fields[$field_info['table']][$field_info['field']] = $field_info['alias'];
     }
     foreach ($this->tables as $alias => $table_info) {
       if ($table = reset($this->databaseContents[$table_info['table']])) {
@@ -256,8 +256,8 @@ protected function executeJoins() {
    */
   protected function getNewRow($table_alias, $fields, $candidate_row, $row = array()) {
     $new_row[$table_alias]['all'] = $candidate_row;
-    foreach ($fields[$table_alias] as $field => $v) {
-      $new_row[$table_alias]['result'][$field] = $candidate_row[$field];
+    foreach ($fields[$table_alias] as $field => $alias) {
+      $new_row[$table_alias]['result'][$alias] = $candidate_row[$field];
     }
     return $new_row + $row;
   }
diff --git a/core/modules/migrate_drupal/tests/src/Unit/source/d6/NodeByNodeTypeTest.php b/core/modules/migrate_drupal/tests/src/Unit/source/d6/NodeByNodeTypeTest.php
index ae2123e..2370bd8 100644
--- a/core/modules/migrate_drupal/tests/src/Unit/source/d6/NodeByNodeTypeTest.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/d6/NodeByNodeTypeTest.php
@@ -86,9 +86,10 @@ class NodeByNodeTypeTest extends MigrateSqlSourceTestCase {
    */
   protected function setUp() {
     $database_contents = $this->expectedResults;
-    array_walk($this->expectedResults, function ($row) {
+    array_walk($this->expectedResults, function (&$row) {
       $row['node_uid'] = $row['uid'];
       $row['revision_uid'] = $row['uid'] + 1;
+      unset($row['uid']);
     });
 
     $database_contents[] = array(
diff --git a/core/modules/migrate_drupal/tests/src/Unit/source/d6/NodeTest.php b/core/modules/migrate_drupal/tests/src/Unit/source/d6/NodeTest.php
index b2621be..a108f61 100644
--- a/core/modules/migrate_drupal/tests/src/Unit/source/d6/NodeTest.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/d6/NodeTest.php
@@ -124,9 +124,10 @@ protected function setUp() {
       }
       $this->databaseContents['node'][$k] = $row;
     }
-    array_walk($this->expectedResults, function ($row) {
+    array_walk($this->expectedResults, function (&$row) {
       $row['node_uid'] = $row['uid'];
       $row['revision_uid'] = $row['uid'] + 1;
+      unset($row['uid']);
     });
 
     parent::setUp();