diff --git a/daphne/endpoints.py b/daphne/endpoints.py
index 6b89953..b25a7e1 100644
--- a/daphne/endpoints.py
+++ b/daphne/endpoints.py
@@ -1,10 +1,12 @@
 from abc import ABC, abstractmethod
 
+
 class Endpoint(ABC):
     @abstractmethod
     def parse(self, options):
         pass
 
+
 class TCPEndpoint(Endpoint):
     def parse(self, options):
         if options.get("port") and options.get("host"):
@@ -14,20 +16,24 @@ class TCPEndpoint(Endpoint):
             raise ValueError("TCP binding requires both port and host kwargs.")
         return None
 
+
 class UNIXEndpoint(Endpoint):
     def parse(self, options):
         if options.get("unix_socket"):
             return f"unix:{options['unix_socket']}"
         return None
 
+
 class FileDescriptorEndpoint(Endpoint):
     def parse(self, options):
         if options.get("file_descriptor") is not None:
             return f"fd:fileno={int(options['file_descriptor'])}"
         return None
 
+
 endpoint_parsers = [TCPEndpoint(), UNIXEndpoint(), FileDescriptorEndpoint()]
 
+
 def build_endpoint_description_strings(**kwargs):
     """
     Build a list of twisted endpoint description strings that the server will listen on.
diff --git a/tests/test_cli.py b/tests/test_cli.py
index aee7f8b..f6c6f78 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -5,10 +5,12 @@ from unittest import TestCase, skipUnless
 
 from daphne.cli import CommandLineInterface
 from daphne.endpoints import (
-    build_endpoint_description_strings as build,
-    endpoint_parsers,
     Endpoint,
 )
+from daphne.endpoints import build_endpoint_description_strings as build
+from daphne.endpoints import (
+    endpoint_parsers,
+)
 
 
 class TestEndpointDescriptions(TestCase):