diff --git a/Makefile b/Makefile
index cb824ef..40da06e 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,7 @@
 
 
 flake:
-	flake8 aiorwlock tests examples
+	flake8 aiorwlock tests examples setup.py
 
 test: flake
 	pytest -s
diff --git a/aiorwlock/__init__.py b/aiorwlock/__init__.py
index f885980..4f762e3 100644
--- a/aiorwlock/__init__.py
+++ b/aiorwlock/__init__.py
@@ -271,5 +271,6 @@ def writer(self) -> _WriterLock:
     writer_lock = writer
 
     def __repr__(self) -> str:
-        return '<RWLock: {} {}>'.format(self.reader_lock.__repr__(),
-                                        self.writer_lock.__repr__())
+        rl = self.reader_lock.__repr__()
+        wl = self.writer_lock.__repr__()
+        return '<RWLock: {} {}>'.format(rl, wl)
diff --git a/setup.py b/setup.py
index 8dc5c0b..9b12650 100644
--- a/setup.py
+++ b/setup.py
@@ -8,7 +8,7 @@
 
 
 if sys.version_info < (3, 5, 3):
-    raise RuntimeError("aiorwlock requires Python 3.5.3+")
+    raise RuntimeError('aiorwlock requires Python 3.5.3+')
 
 
 def read(f):
@@ -27,6 +27,7 @@ def read_version():
         else:
             raise RuntimeError('Cannot find version in aiorwlock/__init__.py')
 
+
 classifiers = [
     'License :: OSI Approved :: Apache Software License',
     'Intended Audience :: Developers',