diff --git a/doc/requirements.txt b/doc/requirements.txt
new file mode 100644
index 0000000..7ddda55
--- /dev/null
+++ b/doc/requirements.txt
@@ -0,0 +1,5 @@
+sphinx>=1.8.0,!=2.1.0;python_version>='3.4' # BSD
+sphinxcontrib-httpdomain>=1.3.0 # BSD
+sphinxcontrib-pecanwsme>=0.8.0 # Apache-2.0
+openstackdocstheme>=1.30.0 # Apache-2.0
+reno>=2.5.0 # Apache-2.0
diff --git a/doc/source/_static/.placeholder b/doc/source/_static/.placeholder
new file mode 100644
index 0000000..e69de29
diff --git a/test-requirements.txt b/test-requirements.txt
index e785be3..807c375 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -2,11 +2,4 @@
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
 
-hacking>=1.1.0,<1.2.0 # Apache-2.0
-
-sphinx>=1.8.0,<2.0.0;python_version=='2.7' # BSD
-sphinx>=1.8.0,!=2.1.0;python_version>='3.4' # BSD
-openstackdocstheme>=1.18.1 # Apache-2.0
-
-# releasenotes
-reno>=2.5.0 # Apache-2.0
+hacking>=1.1.0 # Apache-2.0
diff --git a/tox.ini b/tox.ini
index 7a8bf1a..57af5f9 100644
--- a/tox.ini
+++ b/tox.ini
@@ -34,11 +34,12 @@ commands =
     coverage xml -o cover/coverage.xml
 
 [testenv:docs]
+deps = -r{toxinidir}/doc/requirements.txt
 whitelist_externals =
   rm
 commands =
   rm -fr doc/build
-  sphinx-build -W -d doc/build/doctrees --keep-going -b html doc/source/ doc/build/html
+  sphinx-build -E -W --keep-going -b html doc/source doc/build/html
 
 [testenv:releasenotes]
 whitelist_externals =
@@ -52,8 +53,7 @@ commands = oslo_debug_helper {posargs}
 
 [flake8]
 # E123, E125 skipped as they are invalid PEP-8.
-
 show-source = True
-ignore = E123,E125
+ignore = E123,E125,W504
 builtins = _
 exclude=.venv,.git,.tox,dist,doc,*lib/python*,*egg,build