diff --git a/application/Espo/Core/Formula/Functions/EntityGroup/SumRelatedType.php b/application/Espo/Core/Formula/Functions/EntityGroup/SumRelatedType.php
index c136914da1..5beb84e197 100644
--- a/application/Espo/Core/Formula/Functions/EntityGroup/SumRelatedType.php
+++ b/application/Espo/Core/Formula/Functions/EntityGroup/SumRelatedType.php
@@ -113,11 +113,31 @@ class SumRelatedType extends \Espo\Core\Formula\Functions\Base
             $foreignSelectManager->addJoin($foreignLink, $selectParams);
         }
 
-        $selectParams['groupBy'] = [$foreignLink . '.id'];
+        if (!empty($selectParams['distinct'])) {
+            $sqSelectParams = $selectParams;
 
-        $selectParams['whereClause'][] = [
-            $foreignLink . '.id' => $entity->id
-        ];
+            $sqSelectParams['whereClause'][] = [
+                $foreignLink . '.id' => $entity->id
+            ];
+
+            $sqSelectParams['select'] = ['id'];
+            unset($sqSelectParams['distinct']);
+            unset($sqSelectParams['orderBy']);
+            unset($sqSelectParams['order']);
+
+            $selectParams['whereClause'][] = [
+                'id=s' => [
+                    'entityType' => $foreignEntityType,
+                    'selectParams' => $sqSelectParams,
+                ]
+            ];
+        } else {
+            $selectParams['whereClause'][] = [
+                $foreignLink . '.id' => $entity->id
+            ];
+        }
+
+        $selectParams['groupBy'] = [$foreignLink . '.id'];
 
         $entityManager->getRepository($foreignEntityType)->handleSelectParams($selectParams);
 
diff --git a/tests/integration/Espo/Core/Formula/FormulaTest.php b/tests/integration/Espo/Core/Formula/FormulaTest.php
index ff05631173..d0d9de22bb 100644
--- a/tests/integration/Espo/Core/Formula/FormulaTest.php
+++ b/tests/integration/Espo/Core/Formula/FormulaTest.php
@@ -95,6 +95,37 @@ class FormulaTest extends \tests\integration\Core\BaseTestCase
         $this->assertEquals(40, $result);
     }
 
+    public function testSumRelated()
+    {
+        $em = $this->getContainer()->get('entityManager');
+        $fm = $this->getContainer()->get('formulaManager');
+
+        $contact1 = $em->createEntity('Contact', [
+            'lastName' => '1',
+        ]);
+        $contact2 = $em->createEntity('Contact', [
+            'lastName' => '2',
+        ]);
+
+        $opportunity1 = $em->createEntity('Opportunity', [
+            'name' => '1',
+            'amount' => 1,
+            'stage' => 'Closed Won',
+            'contactsIds' => [$contact1->id, $contact2->id],
+        ]);
+
+        $opportunity2 = $em->createEntity('Opportunity', [
+            'name' => '2',
+            'amount' => 1,
+            'stage' => 'Closed Won',
+            'contactsIds' => [$contact1->id, $contact2->id],
+        ]);
+
+        $script = "entity\sumRelated('opportunities', 'amountConverted', 'won')";
+        $result = $fm->run($script, $contact1);
+        $this->assertEquals(2, $result);
+    }
+
     public function testRecordExists()
     {
         $em = $this->getContainer()->get('entityManager');