diff --git a/opflexagent/vpplib/vpp_papi_provider.py b/opflexagent/vpplib/vpp_papi_provider.py
index 84b74038..154f393c 100644
--- a/opflexagent/vpplib/vpp_papi_provider.py
+++ b/opflexagent/vpplib/vpp_papi_provider.py
@@ -76,7 +76,6 @@ def __init__(self, name, shm_prefix=None, read_timeout=3):
         self.shm_prefix = shm_prefix
         self._expect_api_retval = self._zero
         self._expect_stack = []
-        global vpp_jsonfiles
 
         if not vpp_jsonfiles:
             install_dir = os.getenv('VPP_API_DIR',
diff --git a/test-requirements.txt b/test-requirements.txt
index 59f10ff8..34ebf926 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -1,7 +1,7 @@
 # The order of packages is significant, because pip processes them in the order
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
-hacking>=3.0.1,<3.1.0 # Apache-2.0
+hacking>=7.0.0,<=8.0.0 # Apache-2.0
 
 neutron
 
diff --git a/tox.ini b/tox.ini
index e633d636..afdd4ceb 100644
--- a/tox.ini
+++ b/tox.ini
@@ -59,9 +59,13 @@ commands = {posargs}
 # E126 continuation line over-indented for hanging indent
 # E128 continuation line under-indented for visual indent
 # E129 visually indented line with same indent as next logical line - REVISIT
+# E402: Module level import not at top of file
 # E741 ambiguous variable name - REVISIT
+# H214: Use assertIn/NotIn instead of assertTrue/False for membership tests - REVISIT
+# H216: Use assertIsInstance instead of assertTrue(isinstance(...)) - REVISIT
 # H404 multi line docstring should start with a summary - REVISIT
 # H405 multi line docstring summary not separated with an empty line
+# H904: Delay string formatting (use logging formatting instead of % or f-strings)
 # I202 Additional newline in a group of imports
 # W504 line break after binary operator - REVISIT
 # W605 invalid escape sequence - REVISIT
@@ -70,7 +74,7 @@ commands = {posargs}
 # N530: Direct neutron imports not allowed
 # N535: Usage of Python eventlet module not allowed
 
-ignore = E126,E128,E129,E741,H401,H404,H405,I202,W504,W605,N521,N529,N530,N534,N535
+ignore = E126,E128,E129,E402,E741,H214,H216,H401,H404,H405,H904,I202,W504,W605,N521,N529,N530,N534,N535
 # H106: Don’t put vim configuration in source files
 # H203: Use assertIs(Not)None to check for None
 # H204: Use assert(Not)Equal to check for equality