diff --git a/docker_squash/cli.py b/docker_squash/cli.py
index 73e981d..9663057 100644
--- a/docker_squash/cli.py
+++ b/docker_squash/cli.py
@@ -90,6 +90,7 @@ def run(self):
         parser.add_argument(
             "-m",
             "--message",
+            default="",
             help="Specify a commit message (comment) for the new image.",
         )
         parser.add_argument(
diff --git a/docker_squash/image.py b/docker_squash/image.py
index 35bf6ec..8f0c679 100644
--- a/docker_squash/image.py
+++ b/docker_squash/image.py
@@ -18,7 +18,6 @@
 
 
 class Chdir(object):
-
     """Context manager for changing the current working directory"""
 
     def __init__(self, newPath):