diff --git a/proxy/http/proxy/plugin.py b/proxy/http/proxy/plugin.py
index b44b1a872f..c1dfd34fa4 100644
--- a/proxy/http/proxy/plugin.py
+++ b/proxy/http/proxy/plugin.py
@@ -19,6 +19,7 @@
 from ...common.utils import tls_interception_enabled
 from ...core.connection import TcpServerConnection
 
+
 if TYPE_CHECKING:   # pragma: no cover
     from ...common.types import HostPort
     from ...core.connection import UpstreamConnectionPool
diff --git a/proxy/http/proxy/server.py b/proxy/http/proxy/server.py
index 2361a2bf1d..fcaf3e7306 100644
--- a/proxy/http/proxy/server.py
+++ b/proxy/http/proxy/server.py
@@ -793,8 +793,8 @@ def _wrap_server(
             # we will cache such upstream hosts and avoid intercepting them for future
             # requests.
             logger.warning(
-                "ssl.SSLCertVerificationError: "
-                + "Server raised cert verification error for upstream: {0}".format(
+                'ssl.SSLCertVerificationError: '
+                + 'Server raised cert verification error for upstream: {0}'.format(
                     upstream.addr[0],
                 ),
             )
@@ -802,14 +802,14 @@ def _wrap_server(
         except ssl.SSLError as e:
             if e.reason == 'SSLV3_ALERT_HANDSHAKE_FAILURE':
                 logger.warning(
-                    "{0}: ".format(e.reason)
-                    + "Server raised handshake alert failure for upstream: {0}".format(
+                    '{0}: '.format(e.reason)
+                    + 'Server raised handshake alert failure for upstream: {0}'.format(
                         upstream.addr[0],
                     ),
                 )
             else:
                 logger.exception(
-                    "SSLError when wrapping client for upstream: {0}".format(
+                    'SSLError when wrapping client for upstream: {0}'.format(
                         upstream.addr[0],
                     ),
                     exc_info=e,
diff --git a/proxy/plugin/proxy_pool.py b/proxy/plugin/proxy_pool.py
index a70e3dc18f..eecac398a2 100644
--- a/proxy/plugin/proxy_pool.py
+++ b/proxy/plugin/proxy_pool.py
@@ -15,7 +15,6 @@
 from typing import Any, Dict, List, Optional
 
 from proxy.core.connection import TcpServerConnection
-
 from ..http import Url, httpHeaders, httpMethods
 from ..core.base import TcpUpstreamConnectionHandler
 from ..http.proxy import HttpProxyBasePlugin