diff --git a/doc/requirements.txt b/doc/requirements.txt
index b496bfce..6a760547 100644
--- a/doc/requirements.txt
+++ b/doc/requirements.txt
@@ -1,4 +1,8 @@
-sphinx>=1.7.0,<2.0.0;python_version=='2.7' # BSD
-sphinx>=1.7.0;python_version>='3.4' # BSD
+# The order of packages is significant, because pip processes them in the order
+# of appearance. Changing the order has an impact on the overall integration
+# process, which may cause wedges in the gate later.
+
+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>=1.20.0 # Apache-2.0
 os-api-ref>=1.5.0 # Apache-2.0
diff --git a/lower-constraints.txt b/lower-constraints.txt
index 6a127da1..b6cdcf40 100644
--- a/lower-constraints.txt
+++ b/lower-constraints.txt
@@ -103,7 +103,7 @@ Routes==2.4.1
 simplejson==3.13.2
 six==1.11.0
 snowballstemmer==1.2.1
-Sphinx==1.7.0
+Sphinx==1.8.0
 sphinxcontrib-websupport==1.0.1
 SQLAlchemy==1.2.5
 sqlalchemy-migrate==0.11.0
diff --git a/tox.ini b/tox.ini
index 928b1dfa..34a5243d 100644
--- a/tox.ini
+++ b/tox.ini
@@ -35,7 +35,7 @@ deps =
   -r{toxinidir}/doc/requirements.txt
 commands =
   rm -rf doc/build
-  sphinx-build -W -b html -d doc/build/doctrees doc/source doc/build/html
+  sphinx-build -W --keep-going -b html -d doc/build/doctrees doc/source doc/build/html
 
 [testenv:api-ref]
 # This environment is called from CI scripts to test and publish
@@ -44,7 +44,7 @@ whitelist_externals = rm
 deps = {[testenv:docs]deps}
 commands =
   rm -rf api-ref/build
-  sphinx-build -W -b html -d api-ref/build/doctrees api-ref/source api-ref/build/html
+  sphinx-build -W --keep-going -b html -d api-ref/build/doctrees api-ref/source api-ref/build/html
 
 [flake8]
 # E712 is ignored on purpose, since it is normal to use 'column == true'