diff --git a/aiohttp_debugtoolbar/main.py b/aiohttp_debugtoolbar/main.py
index 1a5de3cc..bb7c3096 100644
--- a/aiohttp_debugtoolbar/main.py
+++ b/aiohttp_debugtoolbar/main.py
@@ -10,6 +10,7 @@
     ToolbarStorage, ExceptionHistory
 from .views import ExceptionDebugView
 
+
 default_panel_names = [
     panels.HeaderDebugPanel,
     panels.PerformanceDebugPanel,
@@ -18,6 +19,7 @@
     panels.LoggingPanel,
 ]
 
+
 default_global_panel_names = [
     panels.RoutesDebugPanel,
     panels.SettingsDebugPanel,
@@ -25,6 +27,7 @@
     panels.VersionDebugPanel,
 ]
 
+
 default_settings = {
     'enabled': True,
     'intercept_exc': 'debug',  # display or debug or False
diff --git a/aiohttp_debugtoolbar/tbtools/repr.py b/aiohttp_debugtoolbar/tbtools/repr.py
index daecaf17..5234d625 100644
--- a/aiohttp_debugtoolbar/tbtools/repr.py
+++ b/aiohttp_debugtoolbar/tbtools/repr.py
@@ -83,6 +83,7 @@ def __call__(self, topic=None):
             text = paragraphs[0]
         sys.stdout._write(HELP_HTML % {'title': title, 'text': text})
 
+
 helper = _Helper()
 
 
diff --git a/aiohttp_debugtoolbar/toolbar.py b/aiohttp_debugtoolbar/toolbar.py
index 9796b29e..6ec1bf0d 100644
--- a/aiohttp_debugtoolbar/toolbar.py
+++ b/aiohttp_debugtoolbar/toolbar.py
@@ -79,6 +79,8 @@ def inject(self, request, response):
         response.body = replace_insensitive(
             response_html, b'</body>',
             toolbar_html + b'</body>')
+
+
 toolbar_css_template = """\
 <link rel="stylesheet" type="text/css" href="%(css_path)s">"""
 
diff --git a/requirements-dev.txt b/requirements-dev.txt
index 70fcf488..d91ff16d 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -2,7 +2,7 @@ ipdb==0.10.1
 pytest==3.0.3
 pytest-cov==2.4.0
 coverage==4.2
-flake8==3.0.4
+flake8==3.2.0
 -e .
 aiohttp-jinja2==0.8.0
 aiohttp-mako==0.1.0
diff --git a/tests/pep492/test_await.py b/tests/pep492/test_await.py
index 0620833b..16adfcc1 100644
--- a/tests/pep492/test_await.py
+++ b/tests/pep492/test_await.py
@@ -1,4 +1,3 @@
-import aiohttp
 from aiohttp import web