diff --git a/doc/requirements.txt b/doc/requirements.txt
index 27ac1acd6b..91745ad945 100644
--- a/doc/requirements.txt
+++ b/doc/requirements.txt
@@ -9,6 +9,7 @@ openstackdocstheme>=1.20.0 # Apache-2.0
 reno>=2.5.0 # Apache-2.0
 sphinx!=1.6.6,!=1.6.7,>=1.6.2,<2.0.0;python_version=='2.7' # BSD
 sphinx!=1.6.6,!=1.6.7,!=2.1.0,>=1.6.2;python_version>='3.4' # BSD
+doc8>=0.6.0 # Apache-2.0
 
 # The below is rewquired to build testing module reference
 mock>=2.0.0 # BSD
diff --git a/lower-constraints.txt b/lower-constraints.txt
index 1cc785950a..72232a0295 100644
--- a/lower-constraints.txt
+++ b/lower-constraints.txt
@@ -22,7 +22,6 @@ django-babel==0.6.2
 django-compressor==2.0
 django-debreach==1.4.2
 django-pyscss==2.0.2
-doc8==0.6.0
 docutils==0.11
 dogpile.cache==0.6.2
 dulwich==0.15.0
diff --git a/test-requirements.txt b/test-requirements.txt
index b0c9e44668..f0aef8be40 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -12,7 +12,6 @@ hacking>=1.1.0 # Apache-2.0
 astroid==2.1.0;python_version>='3.0' # LGPLv2.1
 bandit!=1.6.0,>=1.4.0 # Apache-2.0
 coverage!=4.4,>=4.0 # Apache-2.0
-doc8>=0.6.0 # Apache-2.0
 flake8-import-order==0.12 # LGPLv3
 mock>=2.0.0 # BSD
 mox3>=0.20.0 # Apache-2.0
diff --git a/tox.ini b/tox.ini
index 5da8e7ed56..9279c5507e 100644
--- a/tox.ini
+++ b/tox.ini
@@ -37,21 +37,17 @@ deps =
   -r{toxinidir}/requirements.txt
 
 [testenv:venv]
+envdir = {toxworkdir}/venv
 commands = {posargs}
 
 [testenv:pep8]
-# 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}
-  -r{toxinidir}/doc/requirements.txt
+envdir = {toxworkdir}/venv
 setenv =
   DJANGO_SETTINGS_MODULE=openstack_dashboard.test.settings
 commands =
   flake8 {posargs}
   {envpython} {toxinidir}/manage.py extract_messages --verbosity 0 --check-only
   bash {toxinidir}/tools/find_executables.sh
-  doc8 doc/source releasenotes/source releasenotes/notes
   pylint -j 4 --verbose --rcfile=.pylintrc -f colorized openstack_dashboard openstack_auth horizon
 
 [testenv:cover]
@@ -125,6 +121,7 @@ deps =
   -r{toxinidir}/doc/requirements.txt
 commands =
   sphinx-build -W -b html doc/source doc/build/html
+  doc8 doc/source
 
 [testenv:pdf-docs]
 basepython = python3
@@ -141,6 +138,7 @@ envdir = {toxworkdir}/docs
 deps = {[testenv:docs]deps}
 commands =
   sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html
+  doc8 doc/source
 
 [testenv:manage]
 envdir = {toxworkdir}/venv