diff --git a/dagflow/logger.py b/dagflow/logger.py
index f1761eb2bea5c1e65fb279bb2d325559b58b4d59..eb91644d808792758209f36d2db465de766e0c75 100644
--- a/dagflow/logger.py
+++ b/dagflow/logger.py
@@ -6,6 +6,7 @@ from logging import (
     Logger,
     StreamHandler,
     getLogger,
+    addLevelName
 )
 from typing import Optional
 
@@ -42,7 +43,7 @@ def get_logger(
 
 SUBINFO    = INFO-10
 SUBSUBINFO = INFO-20
-logging.addLevelName(SUBINFO, "SUBINFO")
-logging.addLevelName(SUBSUBINFO, "SUBSUBINFO")
+addLevelName(SUBINFO, "SUBINFO")
+addLevelName(SUBSUBINFO, "SUBSUBINFO")
 
 logger = get_logger()