diff --git a/oommfc/__init__.py b/oommfc/__init__.py
index 1f066ac..5312d3f 100644
--- a/oommfc/__init__.py
+++ b/oommfc/__init__.py
@@ -1,4 +1,5 @@
 """OOMMF calculator."""
+
 import importlib.metadata
 
 import pytest
diff --git a/oommfc/oommf/__init__.py b/oommfc/oommf/__init__.py
index 206c09b..8767bb5 100644
--- a/oommfc/oommf/__init__.py
+++ b/oommfc/oommf/__init__.py
@@ -1,4 +1,5 @@
 """OOMMF driving utility"""
+
 from .oommf import (
     DockerOOMMFRunner,
     ExeOOMMFRunner,
diff --git a/tasks.py b/tasks.py
index f87b680..d2d55c5 100644
--- a/tasks.py
+++ b/tasks.py
@@ -1,4 +1,5 @@
 """Tasks to release the package."""
+
 import os
 import shutil