diff --git a/mistraldashboard/action_executions/tables.py b/mistraldashboard/action_executions/tables.py
index 221af9d..d7a4c77 100644
--- a/mistraldashboard/action_executions/tables.py
+++ b/mistraldashboard/action_executions/tables.py
@@ -80,8 +80,7 @@ class ActionExecutionsTable(tables.DataTable):
 
     def getHoverHelp(data):
         if hasattr(data, 'state_info') and data.state_info:
-
-                return {'title': data.state_info}
+            return {'title': data.state_info}
 
     STATE_STATUS_CHOICES = (
         ("success", True),
diff --git a/mistraldashboard/default/smart_cell.py b/mistraldashboard/default/smart_cell.py
index b5404ab..ec148cb 100644
--- a/mistraldashboard/default/smart_cell.py
+++ b/mistraldashboard/default/smart_cell.py
@@ -55,9 +55,9 @@ def get_data(self, datum, column, row):
 
         if (template.defaultfilters.urlize in column.filters or
            template.defaultfilters.yesno in column.filters):
-                data = widget.render(widget_name,
-                                     column.get_raw_data(datum),
-                                     form_field_attributes)
+            data = widget.render(widget_name,
+                                 column.get_raw_data(datum),
+                                 form_field_attributes)
         else:
             data = widget.render(widget_name,
                                  column.get_data(datum),
diff --git a/mistraldashboard/executions/tables.py b/mistraldashboard/executions/tables.py
index 6646457..c150750 100644
--- a/mistraldashboard/executions/tables.py
+++ b/mistraldashboard/executions/tables.py
@@ -158,8 +158,7 @@ class ExecutionsTable(tables.DataTable):
 
     def getHoverHelp(data):
         if hasattr(data, 'state_info') and data.state_info:
-
-                return {'title': data.state_info}
+            return {'title': data.state_info}
 
     STATE_STATUS_CHOICES = (
         ("success", True),
diff --git a/mistraldashboard/tasks/tables.py b/mistraldashboard/tasks/tables.py
index 3fe3df4..86a6a15 100644
--- a/mistraldashboard/tasks/tables.py
+++ b/mistraldashboard/tasks/tables.py
@@ -60,8 +60,7 @@ class TaskTable(tables.DataTable):
 
     def getHoverHelp(data):
         if hasattr(data, 'state_info') and data.state_info:
-
-                return {'title': data.state_info}
+            return {'title': data.state_info}
 
     STATE_STATUS_CHOICES = (
         ("success", True),
diff --git a/mistraldashboard/test/settings.py b/mistraldashboard/test/settings.py
index cd11fb7..77b0544 100644
--- a/mistraldashboard/test/settings.py
+++ b/mistraldashboard/test/settings.py
@@ -16,5 +16,5 @@
 from horizon.test.settings import *  # noqa
 from openstack_dashboard.test.settings import *  # noqa
 
-INSTALLED_APPS = list(INSTALLED_APPS)
+INSTALLED_APPS = list(INSTALLED_APPS)  # noqa: F405
 INSTALLED_APPS.append('mistraldashboard')
diff --git a/requirements.txt b/requirements.txt
index 2b86a46..00cb0ee 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -6,3 +6,4 @@ pbr!=2.1.0,>=2.0.0 # Apache-2.0
 iso8601>=0.1.11 # MIT
 python-mistralclient!=3.2.0,>=3.1.0 # Apache-2.0
 PyYAML>=3.12 # MIT
+horizon>=16.1.0 # Apache-2.0
diff --git a/test-requirements.txt b/test-requirements.txt
index c737881..f424220 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -2,8 +2,8 @@
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
 
-# Hacking already pins down pep8, pyflakes and flake8
-hacking!=0.13.0,<0.14,>=0.12.0 # Apache-2.0
+# hacking should appear first in case something else depends on pep8
+hacking>=2.0.0,<3.0.0 # Apache-2.0
 
 # Testing Requirements
 coverage!=4.4,>=4.0 # Apache-2.0
diff --git a/tox.ini b/tox.ini
index f439fdc..082a5a9 100644
--- a/tox.ini
+++ b/tox.ini
@@ -2,15 +2,15 @@
 minversion = 2.0
 envlist = pep8,py27,py37
 skipsdist = True
+ignore_basepython_conflict = true
 
 [testenv]
 usedevelop = True
-install_command = pip install -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/train} {opts} {packages}
 setenv =
    VIRTUAL_ENV={envdir}
-deps = -r{toxinidir}/requirements.txt
+deps = -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/train}
+       -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
-       http://tarballs.openstack.org/horizon/horizon-master.tar.gz
 commands =
     find . -type f -name "*.pyc" -delete
     /bin/bash run_tests.sh -N --no-pep8 {posargs}