diff --git a/ivatar/middleware.py b/ivatar/middleware.py
index 2f052be..8f3ce10 100644
--- a/ivatar/middleware.py
+++ b/ivatar/middleware.py
@@ -1,9 +1,14 @@
+# -*- coding: utf-8 -*-
 """
 Middleware classes
 """
+
 from django.utils.deprecation import MiddlewareMixin
 
-class MultipleProxyMiddleware(MiddlewareMixin):  # pylint: disable=too-few-public-methods
+
+class MultipleProxyMiddleware(
+    MiddlewareMixin
+):  # pylint: disable=too-few-public-methods
     """
     Middleware to rewrite proxy headers for deployments
     with multiple proxies
@@ -14,5 +19,7 @@ class MultipleProxyMiddleware(MiddlewareMixin):  # pylint: disable=too-few-publi
         Rewrites the proxy headers so that forwarded server is
         used if available.
         """
-        if 'HTTP_X_FORWARDED_SERVER' in request.META:
-            request.META['HTTP_X_FORWARDED_HOST'] = request.META['HTTP_X_FORWARDED_SERVER']
+        if "HTTP_X_FORWARDED_SERVER" in request.META:
+            request.META["HTTP_X_FORWARDED_HOST"] = request.META[
+                "HTTP_X_FORWARDED_SERVER"
+            ]