diff --git a/Makefile b/Makefile
index 702bda91..e9abc768 100644
--- a/Makefile
+++ b/Makefile
@@ -28,7 +28,7 @@ tests:
 
 	flake8 --exclude=__init__.py,memory_profiler.py pycallgraph
 	flake8 --ignore=F403 test
-	flake8 examples
+	flake8 examples --exclude=all.py
 
 doc:
 	cd docs/examples && ./generate.py
diff --git a/examples/graphviz/example_with_submodules/example_with_submodules.py b/examples/graphviz/example_with_submodules/example_with_submodules.py
index 2fb6d042..0324c4bd 100644
--- a/examples/graphviz/example_with_submodules/example_with_submodules.py
+++ b/examples/graphviz/example_with_submodules/example_with_submodules.py
@@ -9,5 +9,6 @@ def main():
     s2 = SubmoduleTwo()
     s2.report()
 
+
 if __name__ == "__main__":
     main()
diff --git a/examples/graphviz/recursive.py b/examples/graphviz/recursive.py
index d61a1b15..4043878d 100755
--- a/examples/graphviz/recursive.py
+++ b/examples/graphviz/recursive.py
@@ -20,5 +20,6 @@ def main():
         for a in xrange(1, 10):
             factorial(a)
 
+
 if __name__ == '__main__':
     main()
diff --git a/examples/graphviz/regexp.py b/examples/graphviz/regexp.py
old mode 100755
new mode 100644
index 63bb2c23..4054668b
--- a/examples/graphviz/regexp.py
+++ b/examples/graphviz/regexp.py
@@ -15,11 +15,11 @@ def main():
     config = Config(include_stdlib=True)
 
     with PyCallGraph(output=graphviz, config=config):
-        reo = compile()
+        reo = compile_regex()
         match(reo)
 
 
-def compile():
+def compile_regex():
     return re.compile('^[abetors]*$')
 
 
@@ -41,5 +41,6 @@ def words():
         'abrasives',
     ]
 
+
 if __name__ == '__main__':
     main()
diff --git a/pycallgraph/output/output.py b/pycallgraph/output/output.py
index 662d5630..f6f3efa5 100644
--- a/pycallgraph/output/output.py
+++ b/pycallgraph/output/output.py
@@ -116,7 +116,7 @@ def debug(self, text):
         self.processor.config.log_debug(text)
 
     @classmethod
-    def add_output_file(cls, subparser, defaults, help):
+    def add_output_file(cls, subparser, defaults, help):  # noqa: A002
         subparser.add_argument(
             '-o', '--output-file', type=str, default=defaults.output_file,
             help=help,
diff --git a/pycallgraph/pycallgraph.py b/pycallgraph/pycallgraph.py
index 6af54287..73e018bb 100644
--- a/pycallgraph/pycallgraph.py
+++ b/pycallgraph/pycallgraph.py
@@ -33,7 +33,7 @@ def __init__(self, output=None, config=None):
     def __enter__(self):
         self.start()
 
-    def __exit__(self, type, value, traceback):
+    def __exit__(self, type, value, traceback):  # noqa: A002
         self.done()
 
     def get_tracer_class(self):
diff --git a/pycallgraph/tracer.py b/pycallgraph/tracer.py
index ffcab158..f83cf424 100644
--- a/pycallgraph/tracer.py
+++ b/pycallgraph/tracer.py
@@ -372,4 +372,5 @@ def wrapper(*rest):
 
     return wrapper
 
+
 inspect.getmodule = simple_memoize(inspect.getmodule)
diff --git a/setup.py b/setup.py
index a2a23800..4641eb38 100755
--- a/setup.py
+++ b/setup.py
@@ -1,13 +1,13 @@
 #!/usr/bin/env python
 
-from os import path
-from setuptools import setup
 import sys
 
+from setuptools import setup
 from setuptools.command.test import test as TestCommand
 
 import pycallgraph
 
+
 # Only install the man page if the correct directory exists
 # XXX: Commented because easy_install doesn't like it
 #man_path = '/usr/share/man/man1/'
@@ -15,8 +15,8 @@
 #    data_files=[['/usr/share/man/man1/', ['man/pycallgraph.1']]]
 #else:
 #    data_files=None
+data_files = None
 
-data_files=None
 
 class PyTest(TestCommand):
 
@@ -30,6 +30,7 @@ def run_tests(self):
         errno = pytest.main(self.test_args)
         sys.exit(errno)
 
+
 setup(
     name='pycallgraph',
     version=pycallgraph.__version__,
@@ -45,15 +46,15 @@ def run_tests(self):
     use_2to3=True,
 
     # TODO: Update download_url
-    download_url =
-    'http://pycallgraph.slowchop.com/files/download/pycallgraph-%s.tar.gz' % \
-        pycallgraph.__version__,
+    download_url=
+    'http://pycallgraph.slowchop.com/files/download/pycallgraph-%s.tar.gz' %
+    pycallgraph.__version__,
 
     # Testing
     tests_require=['pytest'],
-    cmdclass = {'test': PyTest},
+    cmdclass={'test': PyTest},
 
-    classifiers = [
+    classifiers=[
         'Development Status :: 4 - Beta',
         'Intended Audience :: Developers',
         'License :: OSI Approved :: GNU General Public License (GPL)',
@@ -68,4 +69,3 @@ def run_tests(self):
         'Topic :: Software Development :: Debuggers',
     ],
 )
-
diff --git a/test/conftest.py b/test/conftest.py
index b54e2531..b8b7a0f5 100644
--- a/test/conftest.py
+++ b/test/conftest.py
@@ -1,6 +1,7 @@
+from pycallgraph import PyCallGraph, Config
 import tempfile
 
-from helpers import *
+import pytest
 
 
 @pytest.fixture(scope='module')
diff --git a/test/helpers.py b/test/helpers.py
index 4ea4abbb..0bbee370 100644
--- a/test/helpers.py
+++ b/test/helpers.py
@@ -1,13 +1,6 @@
 # flake8: noqa
 import time
 
-import pytest
-
-import fix_path
-from pycallgraph import *
-from pycallgraph.tracer import *
-from pycallgraph.output import *
-
 
 def wait_100ms():
     time.sleep(0.1)
diff --git a/test/test_color.py b/test/test_color.py
index 0d33fc51..535a577a 100644
--- a/test/test_color.py
+++ b/test/test_color.py
@@ -1,4 +1,6 @@
-from helpers import *
+from pycallgraph import ColorException, Color
+
+import pytest
 
 
 def test_bad_range():
diff --git a/test/test_config.py b/test/test_config.py
index 5d5335fd..ce0cbc22 100644
--- a/test/test_config.py
+++ b/test/test_config.py
@@ -1,4 +1,4 @@
-from helpers import *
+from pycallgraph.config import Config
 
 
 def test_init():
diff --git a/test/test_gephi.py b/test/test_gephi.py
index 15dd7087..f3f2dfad 100644
--- a/test/test_gephi.py
+++ b/test/test_gephi.py
@@ -1,5 +1,10 @@
-from helpers import *
-from calls import *
+from pycallgraph import PyCallGraph
+from pycallgraph.output.gephi import GephiOutput
+import os
+
+import pytest
+
+from calls import one_nop
 
 
 @pytest.fixture
diff --git a/test/test_graphviz.py b/test/test_graphviz.py
index 35d8d8eb..2669aede 100644
--- a/test/test_graphviz.py
+++ b/test/test_graphviz.py
@@ -1,5 +1,10 @@
-from helpers import *
-from calls import *
+from pycallgraph.output.graphviz import GraphvizOutput
+from pycallgraph.pycallgraph import PyCallGraph
+import os
+
+import pytest
+
+from calls import one_nop
 
 
 @pytest.fixture
diff --git a/test/test_output.py b/test/test_output.py
index 9149e5c8..6b17775b 100644
--- a/test/test_output.py
+++ b/test/test_output.py
@@ -1,4 +1,5 @@
-from helpers import *
+from pycallgraph import Config
+from pycallgraph.output import Output
 
 
 def test_set_config():
diff --git a/test/test_pycallgraph.py b/test/test_pycallgraph.py
index bdc7dc47..76a2fbae 100644
--- a/test/test_pycallgraph.py
+++ b/test/test_pycallgraph.py
@@ -1,4 +1,7 @@
-from helpers import *
+from pycallgraph.exceptions import PyCallGraphException
+from pycallgraph.tracer import AsyncronousTracer, SyncronousTracer
+
+import pytest
 
 
 def test_start_no_outputs(pycg):
diff --git a/test/test_script.py b/test/test_script.py
index 0aa90169..fad47e16 100644
--- a/test/test_script.py
+++ b/test/test_script.py
@@ -1,7 +1,5 @@
 import subprocess
 
-from helpers import *
-
 
 def execute(arguments):
     command = 'PYTHONPATH=. scripts/pycallgraph ' + arguments
diff --git a/test/test_trace_processor.py b/test/test_trace_processor.py
index bdf16ccf..7b8a0cf3 100644
--- a/test/test_trace_processor.py
+++ b/test/test_trace_processor.py
@@ -1,9 +1,11 @@
+from pycallgraph.tracer import TraceProcessor
 import re
 import sys
 
-from helpers import *
-import calls
-from pycallgraph.tracer import TraceProcessor
+import pytest
+
+from pycallgraph import Config
+from calls import one_nop, nop
 
 
 @pytest.fixture
@@ -20,7 +22,7 @@ def test_empty(trace_processor):
 
 def test_nop(trace_processor):
     sys.settrace(trace_processor.process)
-    calls.nop()
+    nop()
     sys.settrace(None)
 
     assert trace_processor.call_dict == {
@@ -32,7 +34,7 @@ def test_nop(trace_processor):
 
 def test_one_nop(trace_processor):
     sys.settrace(trace_processor.process)
-    calls.one_nop()
+    one_nop()
     sys.settrace(None)
 
     assert trace_processor.call_dict == {
@@ -45,7 +47,7 @@ def stdlib_trace(trace_processor, include_stdlib):
     trace_processor.config = Config(include_stdlib=include_stdlib)
     sys.settrace(trace_processor.process)
     re.match("asdf", "asdf")
-    calls.one_nop()
+    one_nop()
     sys.settrace(None)
     return trace_processor.call_dict
 
diff --git a/test/test_util.py b/test/test_util.py
index 084c6f31..bf8cf09e 100644
--- a/test/test_util.py
+++ b/test/test_util.py
@@ -1,4 +1,4 @@
-from helpers import *
+from pycallgraph.util import Util
 
 
 def test_human_readable_biyte():