diff --git a/mitmproxy/tools/cmdline.py b/mitmproxy/tools/cmdline.py
index 21369a1ff..eb4a984dc 100644
--- a/mitmproxy/tools/cmdline.py
+++ b/mitmproxy/tools/cmdline.py
@@ -1,5 +1,6 @@
 import argparse
 
+
 def common_options(parser, opts):
     parser.add_argument(
         '--version',