diff --git a/doc/requirements.txt b/doc/requirements.txt
index 024debe8..005a64eb 100644
--- a/doc/requirements.txt
+++ b/doc/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.
 openstackdocstheme>=1.18.1 # 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,>=1.6.2;python_version>='3.4' # BSD
+sphinx>=1.8.0,<2.0.0;python_version=='2.7' # BSD
+sphinx>=1.8.0,!=2.1.0;python_version>='3.4' # BSD
 doc8>=0.6.0 # Apache-2.0
 reno>=2.5.0 # Apache-2.0
 sphinxcontrib-apidoc>=0.2.0  # BSD
diff --git a/tox.ini b/tox.ini
index ce09ed38..c5493893 100644
--- a/tox.ini
+++ b/tox.ini
@@ -56,12 +56,16 @@ deps =
 commands =
   rm -rf doc/build doc/source/reference/api
   doc8 -e .rst CONTRIBUTING.rst HACKING.rst README.rst doc/source
-  sphinx-build -W -b html doc/source doc/build/html
+  sphinx-build -W --keep-going -b html doc/source doc/build/html
 
 [testenv:releasenotes]
 basepython = python3
+whitelist_externals =
+  rm
 deps = -r{toxinidir}/doc/requirements.txt
-commands = sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html
+commands =
+  rm -rf releasenotes/build
+  sphinx-build -a -E -W -d releasenotes/build/doctrees --keep-going -b html releasenotes/source releasenotes/build/html
 
 [flake8]
 # E123, E125 skipped as they are invalid PEP-8.