diff --git a/datetimerange/__version__.py b/datetimerange/__version__.py
index 8791395..a0ef022 100644
--- a/datetimerange/__version__.py
+++ b/datetimerange/__version__.py
@@ -6,6 +6,6 @@
 __author__ = "Tsuyoshi Hombashi"
 __copyright__ = "Copyright 2016-{}, {}".format(datetime.now().year, __author__)
 __license__ = "MIT License"
-__version__ = "0.5.2"
+__version__ = "0.5.3"
 __maintainer__ = __author__
 __email__ = "tsuyoshi.hombashi@gmail.com"