diff --git a/pytest_localserver/http.py b/pytest_localserver/http.py
index 493d450..a4c3bef 100644
--- a/pytest_localserver/http.py
+++ b/pytest_localserver/http.py
@@ -15,7 +15,6 @@
 
 
 class WSGIServer(threading.Thread):
-
     """
     HTTP server running a WSGI application in its own thread.
     """
@@ -61,7 +60,6 @@ def _encode_chunk(chunk, charset):
 
 
 class ContentServer(WSGIServer):
-
     """
     Small test server which can be taught which content (i.e. string) to serve
     with which response code. Try the following snippet for testing API calls::
diff --git a/pytest_localserver/https.py b/pytest_localserver/https.py
index 2432774..eca0f6a 100644
--- a/pytest_localserver/https.py
+++ b/pytest_localserver/https.py
@@ -13,7 +13,6 @@
 
 
 class SecureContentServer(ContentServer):
-
     """
     Small test server which works just like :class:`http.Server` over HTTP::
 
diff --git a/pytest_localserver/smtp.py b/pytest_localserver/smtp.py
index 82dbc39..532d80a 100644
--- a/pytest_localserver/smtp.py
+++ b/pytest_localserver/smtp.py
@@ -31,7 +31,6 @@ async def handle_DATA(self, server, session, envelope):
 
 
 class Server(aiosmtpd.controller.Controller):
-
     """
     Small SMTP test server.