diff --git a/atrcopy/__init__.py b/atrcopy/__init__.py
index ca7cd15..e3329a7 100644
--- a/atrcopy/__init__.py
+++ b/atrcopy/__init__.py
@@ -1,4 +1,4 @@
-__version__ = "3.4.0"
+__version__ = "4.0.0"
 
 import logging