diff --git a/openapi_core/__init__.py b/openapi_core/__init__.py
index b0e002a..836c9f7 100644
--- a/openapi_core/__init__.py
+++ b/openapi_core/__init__.py
@@ -5,7 +5,7 @@ from openapi_core.shortcuts import (
 
 __author__ = 'Artur Maciąg'
 __email__ = 'maciag.artur@gmail.com'
-__version__ = '0.3.4'
+__version__ = '0.4.0'
 __url__ = 'https://github.com/p1c2u/openapi-core'
 __license__ = 'BSD 3-Clause License'