diff --git a/application/Espo/ORM/DB/BaseMapper.php b/application/Espo/ORM/DB/BaseMapper.php
index 23cf06035b..1e6745d9d5 100644
--- a/application/Espo/ORM/DB/BaseMapper.php
+++ b/application/Espo/ORM/DB/BaseMapper.php
@@ -342,14 +342,10 @@ abstract class BaseMapper implements Mapper
                     $additionalColumnsConditions = $params['additionalColumnsConditions'];
                 }
 
-                $MMJoinPart = $this->getMMJoin($entity, $relationName, $keySet, $additionalColumnsConditions);
+                $params['joins'] = $params['joins'] ?? [];
+
+                $params['joins'][] = $this->getManyManyJoin($entity, $relationName, $additionalColumnsConditions);
 
-                if (empty($params['customJoin'])) {
-                    $params['customJoin'] = '';
-                } else {
-                    $params['customJoin'] .= ' ';
-                }
-                $params['customJoin'] .= $MMJoinPart;
 
                 $params['relationName'] = $relDefs['relationName'];
 
@@ -1274,38 +1270,41 @@ abstract class BaseMapper implements Mapper
         return $entity;
     }
 
-    protected function getMMJoin(Entity $entity, string $relationName, $keySet = false, $conditions = []) : string
+    protected function getManyManyJoin(Entity $entity, string $relationName, ?array $conditions = null) : array
     {
-        $relDefs = $entity->relations[$relationName];
+        $defs = $entity->relations[$relationName];
 
-        if (empty($keySet)) {
-            $keySet = $this->query->getKeys($entity, $relationName);
-        }
+        $middleName = $defs['relationName'] ?? null;
+
+        $keySet = $this->query->getKeys($entity, $relationName);
 
         $key = $keySet['key'];
         $foreignKey = $keySet['foreignKey'];
         $nearKey = $keySet['nearKey'];
         $distantKey = $keySet['distantKey'];
 
-        $relTable = $this->toDb($relDefs['relationName']);
-        $distantTable = $this->toDb($relDefs['entity']);
+        if (!$middleName) {
+            throw new Error("No 'relationName' parameter for '{$relationName}' relationship.");
+        }
 
-        $join =
-            "JOIN `{$relTable}` ON {$distantTable}." . $this->toDb($foreignKey) . " = {$relTable}." . $this->toDb($distantKey)
-            . " AND "
-            . "{$relTable}." . $this->toDb($nearKey) . " = " . $this->pdo->quote($entity->get($key))
-            . " AND "
-            . "{$relTable}.deleted = " . $this->quote(false) . "";
+        $alias = lcfirst($middleName);
+
+        $join = [
+            ucfirst($middleName),
+            $alias,
+            [
+                "{$distantKey}:" => $foreignKey,
+                "{$nearKey}" => $entity->get($key),
+                "deleted" => false,
+            ],
+        ];
 
         $conditions = $conditions ?? [];
-        if (!empty($relDefs['conditions']) && is_array($relDefs['conditions'])) {
-            $conditions = array_merge($conditions, $relDefs['conditions']);
+        if (!empty($defs['conditions']) && is_array($defs['conditions'])) {
+            $conditions = array_merge($conditions, $defs['conditions']);
         }
 
-        if (!empty($conditions)) {
-            $conditionsSql = $this->query->buildJoinConditionsStatement($entity->getEntityType(), $relTable, $conditions);
-            $join .= " AND " . $conditionsSql;
-        }
+        $join[2] = array_merge($join[2], $conditions);
 
         return $join;
     }
diff --git a/application/Espo/ORM/DB/Query/BaseQuery.php b/application/Espo/ORM/DB/Query/BaseQuery.php
index 9adb33d4d2..1b9e070f69 100644
--- a/application/Espo/ORM/DB/Query/BaseQuery.php
+++ b/application/Espo/ORM/DB/Query/BaseQuery.php
@@ -684,13 +684,13 @@ abstract class BaseQuery
         }
 
         if (
-            !empty($params['additionalColumns']) && is_array($params['additionalColumns']) &&
-            !empty($params['relationName'])
+            !empty($params['additionalColumns']) && is_array($params['additionalColumns']) && !empty($params['relationName'])
         ) {
+            $alias = $this->sanitizeSelectAlias(lcfirst($params['relationName']));
+
             foreach ($params['additionalColumns'] as $column => $field) {
                 $itemAlias = $this->sanitizeSelectAlias($field);
-                $selectPart .= ", `" . $this->toDb($this->sanitize($params['relationName'])) . "`." .
-                    $this->toDb($this->sanitize($column)) . " AS `{$itemAlias}`";
+                $selectPart .= ", " . $alias . "." . $this->toDb($this->sanitize($column)) . " AS `{$itemAlias}`";
             }
         }
 
@@ -2035,23 +2035,6 @@ abstract class BaseQuery
         return implode(' ', $joinSqlList);
     }
 
-    public function buildJoinConditionsStatement(string $entityType, string $alias, array $conditions) : string
-    {
-        $entity = $this->getSeed($entityType);
-
-        $sql = '';
-
-        $joinSqlList = [];
-        foreach ($conditions as $left => $right) {
-            $joinSqlList[] = $this->buildJoinConditionStatement($entity, $alias, $left, $right);
-        }
-        if (count($joinSqlList)) {
-            $sql .= implode(" AND ", $joinSqlList);
-        }
-
-        return $sql;
-    }
-
     protected function buildJoinConditionStatement(Entity $entity, $alias = null, $left, $right)
     {
         $sql = '';
diff --git a/tests/unit/Espo/ORM/DB/MapperTest.php b/tests/unit/Espo/ORM/DB/MapperTest.php
index b1f9e56e98..d537f05702 100644
--- a/tests/unit/Espo/ORM/DB/MapperTest.php
+++ b/tests/unit/Espo/ORM/DB/MapperTest.php
@@ -248,15 +248,15 @@ class DBMapperTest extends \PHPUnit\Framework\TestCase
         $query =
             "SELECT tag.id AS `id`, tag.name AS `name`, tag.deleted AS `deleted` ".
             "FROM `tag` ".
-            "JOIN `post_tag` ON tag.id = post_tag.tag_id AND post_tag.post_id = '1' AND post_tag.deleted = 0 ".
+            "JOIN `post_tag` AS `postTag` ON postTag.tag_id = tag.id AND postTag.post_id = '1' AND postTag.deleted = 0 ".
             "WHERE tag.deleted = 0";
-        $return = new MockDBResult(array(
-            array(
+        $return = new MockDBResult([
+            [
                 'id' => '1',
                 'name' => 'test',
                 'deleted' => false,
-            ),
-        ));
+            ],
+        ]);
         $this->mockQuery($query, $return);
         $this->post->id = '1';
         $list = $this->db->selectRelated($this->post, 'tags');
@@ -266,10 +266,34 @@ class DBMapperTest extends \PHPUnit\Framework\TestCase
         $this->assertEquals($list[0]->get('name'), 'test');
     }
 
+    public function testSelectRelatedManyManyWithConditions()
+    {
+        $query =
+            "SELECT team.id AS `id`, team.name AS `name`, team.deleted AS `deleted`, entityTeam.team_id AS `stub` FROM `team` ".
+            "JOIN `entity_team` AS `entityTeam` ON entityTeam.team_id = team.id AND entityTeam.entity_id = '1' AND " .
+            "entityTeam.deleted = 0 AND entityTeam.entity_type = 'Account' WHERE team.deleted = 0";
+        $return = new MockDBResult([
+            [
+                'id' => '1',
+                'name' => 'test',
+                'deleted' => false,
+            ],
+        ]);
+        $this->mockQuery($query, $return);
+        $this->account->id = '1';
+
+        $list = $this->db->selectRelated($this->account, 'teams', [
+            'additionalColumns' => [
+                'teamId' => 'stub',
+            ],
+        ]);
+    }
+
     public function testSelectRelatedHasChildren()
     {
         $query =
-            "SELECT note.id AS `id`, note.name AS `name`, note.parent_id AS `parentId`, note.parent_type AS `parentType`, note.deleted AS `deleted` ".
+            "SELECT ".
+            "note.id AS `id`, note.name AS `name`, note.parent_id AS `parentId`, note.parent_type AS `parentType`, note.deleted AS `deleted` ".
             "FROM `note` ".
             "WHERE note.parent_id = '1' AND note.parent_type = 'Post' AND note.deleted = 0";
         $return = new MockDBResult(array(
@@ -291,7 +315,10 @@ class DBMapperTest extends \PHPUnit\Framework\TestCase
     public function testSelectRelatedBelongsTo()
     {
         $query =
-            "SELECT post.id AS `id`, post.name AS `name`, NULLIF(TRIM(CONCAT(IFNULL(createdBy.salutation_name, ''), IFNULL(createdBy.first_name, ''), ' ', IFNULL(createdBy.last_name, ''))), '') AS `createdByName`, post.created_by_id AS `createdById`, post.deleted AS `deleted` ".
+            "SELECT ".
+            "post.id AS `id`, post.name AS `name`, NULLIF(TRIM(CONCAT(IFNULL(createdBy.salutation_name, ''), ".
+            "IFNULL(createdBy.first_name, ''), ' ', IFNULL(createdBy.last_name, ''))), '') AS `createdByName`, ".
+            "post.created_by_id AS `createdById`, post.deleted AS `deleted` ".
             "FROM `post` ".
             "LEFT JOIN `user` AS `createdBy` ON post.created_by_id = createdBy.id " .
             "WHERE post.id = '1' AND post.deleted = 0 ".
@@ -320,7 +347,7 @@ class DBMapperTest extends \PHPUnit\Framework\TestCase
         $query =
             "SELECT COUNT(tag.id) AS `value` ".
             "FROM `tag` ".
-            "JOIN `post_tag` ON tag.id = post_tag.tag_id AND post_tag.post_id = '1' AND post_tag.deleted = 0 ".
+            "JOIN `post_tag` AS `postTag` ON postTag.tag_id = tag.id AND postTag.post_id = '1' AND postTag.deleted = 0 ".
             "WHERE tag.deleted = 0";
         $return = new MockDBResult([
             [
diff --git a/tests/unit/testData/DB/Entities.php b/tests/unit/testData/DB/Entities.php
index 30cb1db7b0..d59afc6111 100644
--- a/tests/unit/testData/DB/Entities.php
+++ b/tests/unit/testData/DB/Entities.php
@@ -24,6 +24,10 @@ class Account extends TEntity
                 'type' => Entity::BOOL,
                 'default' => 0,
             ),
+            'stub' => [
+                'type' => 'varchar',
+                'notStorable' => true,
+            ],
     );
     public $relations = array(
             'teams' => array(