diff --git a/tox.ini b/tox.ini
index 829d1aac..2ef75ce4 100644
--- a/tox.ini
+++ b/tox.ini
@@ -5,7 +5,7 @@ skipsdist = True
 
 [testenv]
 install_command = pip install \
-    -chttps://opendev.org/openstack/requirements/raw/branch/stable/stein/upper-constraints.txt \
+    -c{env:UPPER_CONSTRAINTS_FILE:https://opendev.org/openstack/requirements/raw/branch/stable/stein/upper-constraints.txt} \
     {opts} {packages}
 setenv = VIRTUAL_ENV={envdir}
          OS_STDOUT_CAPTURE=1
@@ -83,13 +83,14 @@ commands =
 # F901 'raise NotImplemented' should be 'raise NotImplementedError'
 # - bugbear -
 # B008 Do not perform calls in argument defaults. The call is performed only once at function definition time.
+# B009 Do not call getattr with a constant attribute value, it is not any safer than normal property access.
 # B014 Redundant exception types
 ignore= E402,
         H102,H104,H105,H106,H306,H401,H403,H404,H405,H501,
         W504,W605,
         E741,
         F811,F821,F841,F901,
-        B008,B014
+        B008,B009,B014
 # Enable checks which are off by default
 # H106 Don’t put vim configuration in source files (off by default). SHOULD BE ENABLED.
 # H203 Use assertIs(Not)None to check for None (off by default).