diff --git a/migrate/versioning/repository.py b/migrate/versioning/repository.py
index b317eda..8c8cd3b 100644
--- a/migrate/versioning/repository.py
+++ b/migrate/versioning/repository.py
@@ -62,7 +62,7 @@ class Changeset(dict):
 
     def run(self, *p, **k):
         """Run the changeset scripts"""
-        for version, script in self:
+        for ver, script in self:
             script.run(*p, **k)
 
 
diff --git a/migrate/versioning/util/__init__.py b/migrate/versioning/util/__init__.py
index a4ddd73..7ad226b 100644
--- a/migrate/versioning/util/__init__.py
+++ b/migrate/versioning/util/__init__.py
@@ -164,7 +164,7 @@ def with_engine(f, *a, **kw):
             engine.dispose()
 
 
-class Memoize:
+class Memoize(object):
     """Memoize(fn) - an instance which acts like fn but memoizes its arguments
        Will only work on functions with non-mutable arguments
 
diff --git a/migrate/versioning/version.py b/migrate/versioning/version.py
index cec75c0..de7008f 100644
--- a/migrate/versioning/version.py
+++ b/migrate/versioning/version.py
@@ -252,7 +252,7 @@ class Version(object):
         self.python = script.PythonScript(path)
 
 
-class Extensions:
+class Extensions(object):
     """A namespace for file extensions"""
     py = 'py'
     sql = 'sql'
diff --git a/test-requirements.txt b/test-requirements.txt
index 573ce34..cd5cb69 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -1,8 +1,8 @@
 # Install bounded pep8/pyflakes first, then let flake8 install
-pep8==1.4.5
-pyflakes>=0.7.2,<0.7.4
-flake8==2.0
-hacking>=0.8.0,<0.9
+pep8==1.5.7
+pyflakes==0.8.1
+flake8>=2.2.4,<=2.4.1
+hacking>=0.10.0,<0.11
 
 coverage>=3.6
 discover
diff --git a/tox.ini b/tox.ini
index 57dedd3..fb2be51 100644
--- a/tox.ini
+++ b/tox.ini
@@ -80,6 +80,8 @@ commands =
   python setup.py testr --slowest --testr-args='{posargs}'
 
 [flake8]
+# E111 indentation is not a multiple of four
+# E113 unexpected indentation
 # E121 continuation line indentation is not a multiple of four
 # E122 continuation line missing indentation or outdented
 # E123 closing bracket does not match indentation of opening bracket's line
@@ -88,12 +90,15 @@ commands =
 # E126 continuation line over-indented for hanging indent
 # E127 continuation line over-indented for visual indent
 # E128 continuation line under-indented for visual indent
+# E129 visually indented line with same indent as next logical line
+# E131 continuation line unaligned for hanging indent
 # E202 whitespace before ')'
 # E203 whitespace before ','
 # E225 missing whitespace around operator
 # E226 missing whitespace around arithmetic operator
 # E228 missing whitespace around modulo operator
 # E231 missing whitespace after ','
+# E265 block comment should start with '# '
 # H234 assertEquals is deprecated, use assertEqual
 # E251 unexpected spaces around keyword / parameter equals
 # E261 at least two spaces before inline comment
@@ -122,9 +127,10 @@ commands =
 # H402 one line docstring needs punctuation.
 # H403 multi line docstring end on new line
 # H404 multi line docstring should start with a summary
+# H405 multi line docstring summary not separated with an empty line
 # H501 Do not use locals() for string formatting
 # W391 blank line at end of file
-ignore = E121,E122,E123,E124,E125,E126,E127,E128,E202,E203,E225,E226,E228,E231,E251,E261,E272,E301,E302,E303,E401,E501,E502,E702,E712,F401,F403,F811,F821,F841,H101,H201,H202,H233,H234,H301,H302,H306,H401,H402,H403,H404,H501,W391
+ignore = E111,E113,E121,E122,E123,E124,E125,E126,E127,E128,E129,E131,E202,E203,E225,E226,E228,E231,E251,E261,E265,E272,E301,E302,E303,E401,E501,E502,E702,E712,F401,F403,F811,F821,F841,H101,H201,H202,H233,H234,H301,H302,H306,H401,H402,H403,H404,H405,H501,W391
 show-source = true
 builtins = _
 exclude=.venv,.git,.tox,dist,doc,*openstack/common*,*lib/python*,*egg,tools,build