diff --git a/app/Controller/ExternalTaskCreationController.php b/app/Controller/ExternalTaskCreationController.php
index a1985adb0..501c6e2e3 100644
--- a/app/Controller/ExternalTaskCreationController.php
+++ b/app/Controller/ExternalTaskCreationController.php
@@ -67,7 +67,7 @@ class ExternalTaskCreationController extends BaseController
                 'errors' => $errors,
                 'template' => $taskProvider->getCreationFormTemplate(),
                 'columns_list' => $this->columnModel->getList($project['id']),
-                'users_list' => $this->projectUserRoleModel->getAssignableUsersList($project['id'], true, false, true),
+                'users_list' => $this->projectUserRoleModel->getAssignableUsersList($project['id'], true, false, $project['is_private'] == 1),
                 'categories_list' => $this->categoryModel->getList($project['id']),
                 'swimlanes_list' => $this->swimlaneModel->getList($project['id'], false, true),
             )));