diff --git a/CHANGELOG.md b/CHANGELOG.md
index 880e7f04146..a40c39031b3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -21,7 +21,7 @@ The present file will list all changes made to the project; according to the
 #### Changes
 
 #### Deprecated
-- `Entity::cleanEntitySelectorCache` no longer has any effect as the entity selector is no longer cached as a unique entry
+- `Entity::cleanEntitySelectorCache()` no longer has any effect as the entity selector is no longer cached as a unique entry
 
 #### Removed
 
diff --git a/src/Entity.php b/src/Entity.php
index 212eebaaf61..bb564fede76 100644
--- a/src/Entity.php
+++ b/src/Entity.php
@@ -678,7 +678,7 @@ public function cleanDBonPurge()
      */
     public function cleanEntitySelectorCache()
     {
-        Toolbox::deprecated('Entity::cleanEntitySelectorCache no longer has any effect as the entity selector is no longer cached as a unique entry');
+        Toolbox::deprecated('`Entity::cleanEntitySelectorCache()` no longer has any effect as the entity selector is no longer cached as a unique entry');
     }
 
     public function rawSearchOptions()
@@ -4146,6 +4146,9 @@ private static function getEntityTree(int $entities_id_root): array
 
         $grouped = [];
         foreach ($iterator as $row) {
+            if (!array_key_exists($row['entities_id'], $grouped)) {
+                $grouped[$row['entities_id']] = [];
+            }
             $grouped[$row['entities_id']][] = [
                 'id'   => $row['id'],
                 'name' => $row['name']
@@ -4157,8 +4160,10 @@ private static function getEntityTree(int $entities_id_root): array
             $tree = [];
             if (array_key_exists($root, $list)) {
                 foreach ($list[$root] as $data) {
-                    $tree[$data['id']]['name'] = $data['name'];
-                    $tree[$data['id']]['tree'] = $fn_construct_tree_from_list($list, $data['id']);
+                    $tree[$data['id']] = [
+                        'name' => $data['name'],
+                        'tree' => $fn_construct_tree_from_list($list, $data['id']),
+                    ];
                 }
             }
             return $tree;
diff --git a/tests/functional/Entity.php b/tests/functional/Entity.php
index b699c9cfdf3..c277e77944c 100644
--- a/tests/functional/Entity.php
+++ b/tests/functional/Entity.php
@@ -1157,7 +1157,90 @@ public function testRename()
         $this->string($new_entity->fields['name'])->isEqualTo('New entity');
     }
 
-    public function testEntitySelector()
+    protected function entityTreeProvider(): iterable
+    {
+        $entity_test_root    = getItemByTypeName('Entity', '_test_root_entity');
+        $entity_test_child_1 = getItemByTypeName('Entity', '_test_child_1');
+        $entity_test_child_2 = getItemByTypeName('Entity', '_test_child_2');
+
+        yield [
+            'entity_id' => 0,
+            'result'    => [
+                0 => [
+                    'name' => 'Root entity',
+                    'tree' => [
+                        $entity_test_root->getID() => [
+                            'name' => $entity_test_root->fields['name'],
+                            'tree' => [
+                                $entity_test_child_1->getID() => [
+                                    'name' => $entity_test_child_1->fields['name'],
+                                    'tree' => [],
+                                ],
+                                $entity_test_child_2->getID() => [
+                                    'name' => $entity_test_child_2->fields['name'],
+                                    'tree' => [],
+                                ]
+                            ]
+                        ]
+                    ]
+                ]
+            ]
+        ];
+
+        yield [
+            'entity_id' => $entity_test_root->getID(),
+            'result'    => [
+                $entity_test_root->getID() => [
+                    'name' => \Entity::sanitizeSeparatorInCompletename($entity_test_root->fields['completename']),
+                    'tree' => [
+                        $entity_test_child_1->getID() => [
+                            'name' => $entity_test_child_1->fields['name'],
+                            'tree' => [],
+                        ],
+                        $entity_test_child_2->getID() => [
+                            'name' => $entity_test_child_2->fields['name'],
+                            'tree' => [],
+                        ]
+                    ]
+                ]
+            ]
+        ];
+
+        yield [
+            'entity_id' => $entity_test_child_1->getID(),
+            'result'    => [
+                $entity_test_child_1->getID() => [
+                    'name' => \Entity::sanitizeSeparatorInCompletename($entity_test_child_1->fields['completename']),
+                    'tree' => [
+                    ]
+                ]
+            ]
+        ];
+
+        yield [
+            'entity_id' => $entity_test_child_2->getID(),
+            'result'    => [
+                $entity_test_child_2->getID() => [
+                    'name' => \Entity::sanitizeSeparatorInCompletename($entity_test_child_2->fields['completename']),
+                    'tree' => [
+                    ]
+                ]
+            ]
+        ];
+    }
+
+    /**
+     * @dataProvider entityTreeProvider
+     */
+    public function testGetEntityTree(int $entity_id, array $result): void
+    {
+        $this->login();
+
+        $entity = $this->newTestedInstance();
+        $this->array($this->callPrivateMethod($entity, 'getEntityTree', $entity_id))->isEqualTo($result);
+    }
+
+    public function testGetEntitySelectorTree(): void
     {
         /** @var \DBmysql $DB */
         global $DB;