diff --git a/tox.ini b/tox.ini
index 13abdc5da7..c783dd27c3 100644
--- a/tox.ini
+++ b/tox.ini
@@ -52,6 +52,7 @@ commands = {posargs}
 
 [testenv:pep8]
 basepython = python3
+# NOTE: Due to doc dependencies, we don't share envdir with "venv".
 # sphinx (precisely Pygments) needs to be installed to make doc8 work properly
 deps =
   {[testenv]deps}
@@ -67,6 +68,7 @@ commands =
 
 [testenv:cover]
 basepython = python3
+envdir = {toxworkdir}/venv
 commands =
   coverage erase
   coverage run {toxinidir}/manage.py test horizon --settings=horizon.test.settings {posargs}
@@ -77,6 +79,7 @@ commands =
 
 [testenv:selenium]
 basepython = python3
+envdir = {toxworkdir}/venv
 setenv =
   {[testenv]setenv}
   WITH_SELENIUM=1
@@ -85,6 +88,7 @@ commands = {[unit_tests]commands}
 
 [testenv:selenium-headless]
 basepython = python3
+envdir = {toxworkdir}/venv
 setenv =
   {[testenv]setenv}
   SELENIUM_HEADLESS=1
@@ -94,6 +98,7 @@ commands = {[unit_tests]commands}
 
 [testenv:selenium-phantomjs]
 basepython = python3
+envdir = {toxworkdir}/venv
 setenv =
   {[testenv]setenv}
   SELENIUM_PHANTOMJS=1
@@ -102,6 +107,7 @@ setenv =
 commands = {[unit_tests]commands}
 
 [testenv:py27integration]
+envdir = {toxworkdir}/py27
 # Run integration tests only
 passenv = AVCONV_INSTALLED
 setenv =
@@ -145,32 +151,28 @@ commands =
 
 [testenv:releasenotes]
 basepython = python3
-# There is no need to install horizon.
-usedevelop = False
-deps =
-  -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt}
-  -r{toxinidir}/doc/requirements.txt
+envdir = {toxworkdir}/docs
+deps = {[testenv:docs]deps}
 commands =
   sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html
 
 [testenv:manage]
 basepython = python3
-# we don't need to install test-requirements.txt
-# modules in requirements.txt are installed due to usedevelop=True
-# so 'deps' can be empty.
-deps =
+envdir = {toxworkdir}/venv
 commands = {envpython} {toxinidir}/manage.py {posargs}
 
 [testenv:runserver]
 basepython = python3
+envdir = {toxworkdir}/venv
 commands = {envpython} {toxinidir}/manage.py runserver {posargs}
 
 [testenv:bandit]
 basepython = python3
+envdir = {toxworkdir}/venv
 commands = bandit -r horizon openstack_auth openstack_dashboard -n5 -x tests -ll
 
 [testenv:bandit-baseline]
-envdir = {toxworkdir}/bandit
+envdir = {toxworkdir}/venv
 basepython = python3
 commands = bandit-baseline -r horizon  openstack_auth openstack_dashboard -n5 -x tests -ii -ll