diff --git a/nicovideo/__init__.py b/nicovideo/__init__.py
index 23c129d..d5ae416 100644
--- a/nicovideo/__init__.py
+++ b/nicovideo/__init__.py
@@ -1,5 +1,5 @@
 """ nicovideo.py: nicovideo API wrapper for Python3. """
 from . import video, errors, user, apirawdicts
 
-__version__ = "4.0.0"
+__version__ = "4.0.1"
 __all__ = ["video", "user", "errors", "apirawdicts"]
diff --git a/pyproject.toml b/pyproject.toml
index 54ffb6a..6b9bde9 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "nicovideo.py"
-version = "4.0.0"
+version = "4.0.1"
 description = "ニコニコ動画のAPIを使用して、動画や投稿者などの情報を取得するライブラリです。"
 license = "MIT"
 authors = ["okaits7534 <okaits@okaits7534.net>"]