diff -u b/core/lib/Drupal/Core/Entity/Query/QueryBase.php b/core/lib/Drupal/Core/Entity/Query/QueryBase.php
--- b/core/lib/Drupal/Core/Entity/Query/QueryBase.php
+++ b/core/lib/Drupal/Core/Entity/Query/QueryBase.php
@@ -175,17 +175,15 @@
    *
    * See andConditionGroup() and orConditionGroup() for more.
    *
-   * @param $conjunction
+   * @param string $conjunction
    *   - AND (default): this is the equivalent of andConditionGroup().
    *   - OR: this is the equivalent of orConditionGroup().
    *
-   * return \Drupal\Core\Entity\Query\ConditionInterface
+   * @return \Drupal\Core\Entity\Query\ConditionInterface
    *   An object holding a group of conditions.
    */
   protected function conditionGroupFactory($conjunction = 'AND') {
-    preg_match('/^.*\\\\/', get_class($this), $matches);
-    $class = $matches[0] .'Condition';
-    return new $class($conjunction, $this);
+    return new namespace\Condition($conjunction, $this);
   }
 
   /**
diff -u b/core/lib/Drupal/Core/Entity/Query/Sql/Condition.php b/core/lib/Drupal/Core/Entity/Query/Sql/Condition.php
--- b/core/lib/Drupal/Core/Entity/Query/Sql/Condition.php
+++ b/core/lib/Drupal/Core/Entity/Query/Sql/Condition.php
@@ -15,6 +15,8 @@
 class Condition extends ConditionBase {
 
   /**
+   * The SQL entity query object this condition belongs to.
+   *
    * @var \Drupal\Core\Entity\Query\Sql\Query
    */
   protected $query;
diff -u b/core/lib/Drupal/Core/Entity/Query/Sql/Query.php b/core/lib/Drupal/Core/Entity/Query/Sql/Query.php
--- b/core/lib/Drupal/Core/Entity/Query/Sql/Query.php
+++ b/core/lib/Drupal/Core/Entity/Query/Sql/Query.php
@@ -317,12 +317,13 @@
   /**
    * Gets the Tables object for this query.
    *
+   * @param \Drupal\Core\Database\Query\SelectInterface $sql_query
+   *   The SQL query object being built.
+   *
    * @return \Drupal\Core\Entity\Query\Sql\TablesInterface
    */
   public function getTables(SelectInterface $sql_query) {
-    preg_match('/^.*\\\\/', get_class($this), $matches);
-    $class = $matches[0] .'Tables';
-    return new $class($sql_query);
+    return new namespace\Tables($sql_query);
   }
 
 }
diff -u b/core/lib/Drupal/Core/Entity/Query/Sql/QueryFactory.php b/core/lib/Drupal/Core/Entity/Query/Sql/QueryFactory.php
--- b/core/lib/Drupal/Core/Entity/Query/Sql/QueryFactory.php
+++ b/core/lib/Drupal/Core/Entity/Query/Sql/QueryFactory.php
@@ -49,9 +49,7 @@
    *   The factored query.
    */
   public function get($entity_type, $conjunction, EntityManager $entity_manager) {
-    preg_match('/^.*\\\\/', get_class($this), $matches);
-    $class = $matches[0] .'Query';
-    return new $class($entity_type, $entity_manager, $conjunction, $this->connection);
+    return new namespace\Query($entity_type, $entity_manager, $conjunction, $this->connection);
   }
 
   /**
@@ -67,9 +65,7 @@
    *   The factored aggregation query.
    */
   public function getAggregate($entity_type, $conjunction, EntityManager $entity_manager) {
-    preg_match('/^.*\\\\/', get_class($this), $matches);
-    $class = $matches[0] .'QueryAggregate';
-    return new $class($entity_type, $entity_manager, $conjunction, $this->connection);
+    return new namespace\QueryAggregate($entity_type, $entity_manager, $conjunction, $this->connection);
   }
 
 }
diff -u b/core/lib/Drupal/Core/Entity/Query/Sql/TablesInterface.php b/core/lib/Drupal/Core/Entity/Query/Sql/TablesInterface.php
--- b/core/lib/Drupal/Core/Entity/Query/Sql/TablesInterface.php
+++ b/core/lib/Drupal/Core/Entity/Query/Sql/TablesInterface.php
@@ -5,14 +5,13 @@
  * Contains \Drupal\Core\Entity\Query\Sql\TablesInterface.
  */
 
-
 namespace Drupal\Core\Entity\Query\Sql;
 
-
 /**
  * Adds tables and fields to the SQL entity query.
  */
 interface TablesInterface {
+
   /**
    * @param string $field
    *   If it contains a dot, then field name dot field column. If it doesn't
@@ -28,2 +27,3 @@
   public function addField($field, $type, $langcode);
+
 }