diff --git a/trains/task.py b/trains/task.py
index d14726f5..0e986d92 100644
--- a/trains/task.py
+++ b/trains/task.py
@@ -149,7 +149,7 @@ class Task(_Task):
             validate = [
                 ('project name', project_name, cls.__main_task.get_project_name()),
                 ('task name', task_name, cls.__main_task.name),
-                ('task type', task_type, cls.__main_task.task_type),
+                ('task type', str(task_type), str(cls.__main_task.task_type)),
             ]
 
             for field, default, current in validate: