diff --git a/.version b/.version
index 8aba935..473bd3e 100644
--- a/.version
+++ b/.version
@@ -1 +1 @@
-0.520
+0.521
diff --git a/setup.py b/setup.py
index 9930e6e..e689637 100644
--- a/setup.py
+++ b/setup.py
@@ -4,5 +4,5 @@ from setuptools import setup
 setup(
     name='pre_commit_dummy_package',
     version='0.0.0',
-    install_requires=['mypy==0.520'],
+    install_requires=['mypy==0.521'],
 )