diff --git a/Makefile b/Makefile
index 9f69944..e862a03 100644
--- a/Makefile
+++ b/Makefile
@@ -82,7 +82,7 @@ install-test: install-servers
 	[ -z "$(TEST_EXTRA_PACKAGES)" ] || pip install $(TEST_EXTRA_PACKAGES)
 
 install-style: install-docs
-	pip install -U flake8==3.5.0 flake8-import-order 'flake8-bugbear>=17.3.0' autopep8
+	pip install -U flake8 flake8-import-order flake8-bugbear autopep8
 	
 style:
 	flake8
diff --git a/setup.cfg b/setup.cfg
index 4635543..ec67785 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -9,6 +9,8 @@ addopts = --tb=short
 # E731: Use a def instead of lambda expr
 # E743: Ambiguous function definition
 ignore = E731, E743
+# E503: Line break occurred before a binary operator
+extend-ignore = W503
 select = C,E,F,W,B,B9
 exclude = .eggs, tests/storage/servers/owncloud/, tests/storage/servers/nextcloud/, tests/storage/servers/baikal/, build/
 application-package-names = tests,vdirsyncer
diff --git a/tests/storage/dav/test_caldav.py b/tests/storage/dav/test_caldav.py
index 3063bbd..e72dd22 100644
--- a/tests/storage/dav/test_caldav.py
+++ b/tests/storage/dav/test_caldav.py
@@ -140,13 +140,13 @@ class TestCalDAVStorage(DAVStorageTests):
         task = s.upload(format_item(TASK_TEMPLATE))[0]
         s.item_types = ('VTODO', 'VEVENT')
 
-        def l():
-            return set(href for href, etag in s.list())
+        def hrefs():
+            return {href for href, etag in s.list()}
 
-        assert l() == {event, task}
+        assert hrefs() == {event, task}
         s.item_types = ('VTODO',)
-        assert l() == {task}
+        assert hrefs() == {task}
         s.item_types = ('VEVENT',)
-        assert l() == {event}
+        assert hrefs() == {event}
         s.item_types = ()
-        assert l() == {event, task}
+        assert hrefs() == {event, task}
diff --git a/tests/storage/test_filesystem.py b/tests/storage/test_filesystem.py
index 39a4880..f9f6c83 100644
--- a/tests/storage/test_filesystem.py
+++ b/tests/storage/test_filesystem.py
@@ -67,10 +67,10 @@ class TestFilesystemStorage(StorageTests):
         calls = []
         exe = 'foo'
 
-        def check_call_mock(l, *args, **kwargs):
+        def check_call_mock(call, *args, **kwargs):
             calls.append(True)
-            assert len(l) == 2
-            assert l[0] == exe
+            assert len(call) == 2
+            assert call[0] == exe
 
         monkeypatch.setattr(subprocess, 'call', check_call_mock)
 
@@ -82,5 +82,5 @@ class TestFilesystemStorage(StorageTests):
         tmpdir.mkdir('.git').mkdir('foo')
         tmpdir.mkdir('a')
         tmpdir.mkdir('b')
-        assert set(c['collection'] for c
-                   in self.storage_class.discover(str(tmpdir))) == {'a', 'b'}
+        assert {c['collection'] for c
+                in self.storage_class.discover(str(tmpdir))} == {'a', 'b'}
diff --git a/tests/unit/utils/test_vobject.py b/tests/unit/utils/test_vobject.py
index cfb52d1..6ebaa04 100644
--- a/tests/unit/utils/test_vobject.py
+++ b/tests/unit/utils/test_vobject.py
@@ -22,9 +22,9 @@ _simple_split = [
 ]
 
 _simple_joined = u'\r\n'.join(
-    [u'BEGIN:VADDRESSBOOK'] +
-    _simple_split +
-    [u'END:VADDRESSBOOK\r\n']
+    [u'BEGIN:VADDRESSBOOK']
+    + _simple_split
+    + [u'END:VADDRESSBOOK\r\n']
 )
 
 
@@ -40,9 +40,9 @@ def test_split_collection_simple(benchmark):
 
 def test_split_collection_multiple_wrappers(benchmark):
     joined = u'\r\n'.join(
-        u'BEGIN:VADDRESSBOOK\r\n' +
-        x +
-        u'\r\nEND:VADDRESSBOOK\r\n'
+        u'BEGIN:VADDRESSBOOK\r\n'
+        + x
+        + u'\r\nEND:VADDRESSBOOK\r\n'
         for x in _simple_split
     )
     given = benchmark(lambda: list(vobject.split_collection(joined)))
@@ -118,19 +118,19 @@ def test_split_collection_timezones():
     )
 
     full = u'\r\n'.join(
-        [u'BEGIN:VCALENDAR'] +
-        items +
-        [timezone, u'END:VCALENDAR']
+        [u'BEGIN:VCALENDAR']
+        + items
+        + [timezone, u'END:VCALENDAR']
     )
 
-    given = set(normalize_item(item)
-                for item in vobject.split_collection(full))
-    expected = set(
+    given = {normalize_item(item)
+             for item in vobject.split_collection(full)}
+    expected = {
         normalize_item(u'\r\n'.join((
             u'BEGIN:VCALENDAR', item, timezone, u'END:VCALENDAR'
         )))
         for item in items
-    )
+    }
 
     assert given == expected
 
diff --git a/vdirsyncer/cli/config.py b/vdirsyncer/cli/config.py
index 87296d9..717eb40 100644
--- a/vdirsyncer/cli/config.py
+++ b/vdirsyncer/cli/config.py
@@ -64,7 +64,7 @@ def _validate_collections_param(collections):
                 e = ValueError(
                     'Expected list of format '
                     '["config_name", "storage_a_name", "storage_b_name"]'
-                    .format(len(collection)))
+                )
                 if len(collection) != 3:
                     raise e
 
diff --git a/vdirsyncer/storage/singlefile.py b/vdirsyncer/storage/singlefile.py
index 1e13f20..f789ef0 100644
--- a/vdirsyncer/storage/singlefile.py
+++ b/vdirsyncer/storage/singlefile.py
@@ -70,9 +70,10 @@ class SingleFileStorage(Storage):
                 args['path'] = subpath
 
                 collection_end = (
-                    placeholder_pos +
-                    2 +  # length of '%s'
-                    len(subpath) - len(path)
+                    placeholder_pos
+                    + 2  # length of '%s'
+                    + len(subpath)
+                    - len(path)
                 )
                 collection = subpath[placeholder_pos:collection_end]
                 args['collection'] = collection
@@ -162,10 +163,11 @@ class SingleFileStorage(Storage):
     def _write(self):
         if self._last_etag is not None and \
            self._last_etag != get_etag_from_file(self.path):
-            raise exceptions.PreconditionFailed(
-                'Some other program modified the file {r!}. Re-run the '
+            raise exceptions.PreconditionFailed((
+                'Some other program modified the file {!r}. Re-run the '
                 'synchronization and make sure absolutely no other program is '
-                'writing into the same file.'.format(self.path))
+                'writing into the same file.'
+            ).format(self.path))
         text = join_collection(
             item.raw for item, etag in self._items.values()
         )
diff --git a/vdirsyncer/sync/__init__.py b/vdirsyncer/sync/__init__.py
index e899868..91d04e8 100644
--- a/vdirsyncer/sync/__init__.py
+++ b/vdirsyncer/sync/__init__.py
@@ -74,9 +74,9 @@ class _StorageInfo(object):
         new_meta = self.status.get_new(ident)
 
         return (
-            new_meta.etag != old_meta.etag and  # etag changed
+            new_meta.etag != old_meta.etag  # etag changed
             # item actually changed
-            (old_meta.hash is None or new_meta.hash != old_meta.hash)
+            and (old_meta.hash is None or new_meta.hash != old_meta.hash)
         )
 
     def set_item_cache(self, ident, item):
diff --git a/vdirsyncer/vobject.py b/vdirsyncer/vobject.py
index d97a057..fedf549 100644
--- a/vdirsyncer/vobject.py
+++ b/vdirsyncer/vobject.py
@@ -375,8 +375,8 @@ class _Component(object):
 
     def __eq__(self, other):
         return (
-            isinstance(other, type(self)) and
-            self.name == other.name and
-            self.props == other.props and
-            self.subcomponents == other.subcomponents
+            isinstance(other, type(self))
+            and self.name == other.name
+            and self.props == other.props
+            and self.subcomponents == other.subcomponents
         )